diff --git a/package-lock.json b/package-lock.json
index b9e1003..8aeed58 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -920,7 +920,8 @@
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           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
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           "version": "1.2.0",
@@ -941,12 +942,14 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -961,17 +964,20 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
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@@ -1088,7 +1094,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -1100,6 +1107,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -1114,6 +1122,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -1121,12 +1130,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.2.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.1",
             "yallist": "^3.0.0"
@@ -1145,6 +1156,7 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -1225,7 +1237,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -1237,6 +1250,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -1322,7 +1336,8 @@
         "safe-buffer": {
           "version": "5.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -1358,6 +1373,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -1377,6 +1393,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -1420,12 +1437,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
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@@ -2032,32 +2051,63 @@
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-      "resolved": "http://registry.npmjs.org/koa-send/-/koa-send-4.1.3.tgz",
-      "integrity": "sha512-3UetMBdaXSiw24qM2Mx5mKmxLKw5ZTPRjACjfhK6Haca55RKm9hr/uHDrkrxhSl5/S1CKI/RivZVIopiatZuTA==",
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/koa-send/-/koa-send-5.0.1.tgz",
+      "integrity": "sha512-tmcyQ/wXXuxpDxyNXv5yNNkdAMdFRqwtegBXUaowiQzUKqJehttS0x2j0eOZDQAyloAth5w6wwBImnFzkUz3pQ==",
       "requires": {
-        "debug": "^2.6.3",
-        "http-errors": "^1.6.1",
-        "mz": "^2.6.0",
+        "debug": "^4.1.1",
+        "http-errors": "^1.7.3",
         "resolve-path": "^1.4.0"
       },
       "dependencies": {
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-          "version": "2.6.9",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
-          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "version": "4.3.4",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.4.tgz",
+          "integrity": "sha512-PRWFHuSU3eDtQJPvnNY7Jcket1j0t5OuOsFzPPzsekD52Zl8qUfFIPEiswXqIvHWGVHOgX+7G/vCNNhehwxfkQ==",
           "requires": {
-            "ms": "2.0.0"
+            "ms": "2.1.2"
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+        },
+        "http-errors": {
+          "version": "1.8.1",
+          "resolved": "https://registry.npmjs.org/http-errors/-/http-errors-1.8.1.tgz",
+          "integrity": "sha512-Kpk9Sm7NmI+RHhnj6OIWDI1d6fIoFAtFt9RLaTMRlg/8w49juAStsrBgp0Dp4OdxdVbRIeKhtCUvoi/RuAhO4g==",
+          "requires": {
+            "depd": "~1.1.2",
+            "inherits": "2.0.4",
+            "setprototypeof": "1.2.0",
+            "statuses": ">= 1.5.0 < 2",
+            "toidentifier": "1.0.1"
+          }
+        },
+        "inherits": {
+          "version": "2.0.4",
+          "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.4.tgz",
+          "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ=="
+        },
+        "ms": {
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
+        },
+        "setprototypeof": {
+          "version": "1.2.0",
+          "resolved": "https://registry.npmjs.org/setprototypeof/-/setprototypeof-1.2.0.tgz",
+          "integrity": "sha512-E5LDX7Wrp85Kil5bhZv46j8jOeboKq5JMmYM3gVGdGH8xFpPWXUMsNrlODCrkoxMEeNi/XZIwuRvY4XNwYMJpw=="
+        },
+        "toidentifier": {
+          "version": "1.0.1",
+          "resolved": "https://registry.npmjs.org/toidentifier/-/toidentifier-1.0.1.tgz",
+          "integrity": "sha512-o5sSPKEkg/DIQNmH43V0/uerLrpzVedkUh8tGNvaeXpfpuwjKenlSox/2O/BTlZUtEe+JG7s5YhEz608PlAHRA=="
         }
       }
     },
     "koa-static-server": {
-      "version": "1.3.4",
-      "resolved": "https://registry.npmjs.org/koa-static-server/-/koa-static-server-1.3.4.tgz",
-      "integrity": "sha512-YBwszbVim1r0RLbc4nWAi/rsfhwy+iQEP82Hg0OAGlI/tc6phpbMask8qndURuq7OobTkTQGmtLdt12Fq7Ojxg==",
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/koa-static-server/-/koa-static-server-1.4.0.tgz",
+      "integrity": "sha512-ZkGzD9+2OZubOL458GL8p7vEGfaneGGKSKIUJw9ftXzn36capQw3Wu5A//o7S10tQNgD1oYs96LGPtqtkcuXbQ==",
       "requires": {
-        "koa-send": "~4.1.0",
+        "koa-send": "^5.0.0",
         "upath": "^1.0.2"
       }
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@@ -2236,16 +2286,6 @@
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
       "integrity": "sha1-VgiurfwAvmwpAd9fmGF4jeDVl8g="
     },
-    "mz": {
-      "version": "2.7.0",
-      "resolved": "https://registry.npmjs.org/mz/-/mz-2.7.0.tgz",
-      "integrity": "sha512-z81GNO7nnYMEhrGh9LeymoE4+Yr0Wn5McHIZMK5cfQCl+NDX08sCZgUc9/6MHni9IWuFLm1Z3HTCXu2z9fN62Q==",
-      "requires": {
-        "any-promise": "^1.0.0",
-        "object-assign": "^4.0.1",
-        "thenify-all": "^1.0.0"
-      }
-    },
     "nan": {
       "version": "2.12.0",
       "resolved": "https://registry.npmjs.org/nan/-/nan-2.12.0.tgz",
@@ -2337,11 +2377,6 @@
       "resolved": "https://registry.npmjs.org/oauth-sign/-/oauth-sign-0.9.0.tgz",
       "integrity": "sha512-fexhUFFPTGV8ybAtSIGbV6gOkSv8UtRbDBnAyLQw4QPKkgNlsH2ByPGtMUqdWkos6YCRmAqViwgZrJc/mRDzZQ=="
     },
-    "object-assign": {
-      "version": "4.1.1",
-      "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.1.tgz",
-      "integrity": "sha1-IQmtx5ZYh8/AXLvUQsrIv7s2CGM="
-    },
     "object-copy": {
       "version": "0.1.0",
       "resolved": "https://registry.npmjs.org/object-copy/-/object-copy-0.1.0.tgz",
@@ -2679,7 +2714,7 @@
     "resolve-path": {
       "version": "1.4.0",
       "resolved": "https://registry.npmjs.org/resolve-path/-/resolve-path-1.4.0.tgz",
-      "integrity": "sha1-xL2p9e+y/OZSR4c6s2u02DT+Fvc=",
+      "integrity": "sha512-i1xevIst/Qa+nA9olDxLWnLk8YZbi8R/7JPbCMcgyWaFR6bKWaexgJgEB5oc2PKMjYdrHynyz0NY+if+H98t1w==",
       "requires": {
         "http-errors": "~1.6.2",
         "path-is-absolute": "1.0.1"
@@ -2687,8 +2722,8 @@
       "dependencies": {
         "http-errors": {
           "version": "1.6.3",
-          "resolved": "http://registry.npmjs.org/http-errors/-/http-errors-1.6.3.tgz",
-          "integrity": "sha1-i1VoC7S+KDoLW/TqLjhYC+HZMg0=",
+          "resolved": "https://registry.npmjs.org/http-errors/-/http-errors-1.6.3.tgz",
+          "integrity": "sha512-lks+lVC8dgGyh97jxvxeYTWQFvh4uw4yC12gVl63Cg30sjPX4wuGcdkICVXDAESr6OJGjqGA8Iz5mkeN6zlD7A==",
           "requires": {
             "depd": "~1.1.2",
             "inherits": "2.0.3",
@@ -3043,22 +3078,6 @@
         "execa": "^0.7.0"
       }
     },
-    "thenify": {
-      "version": "3.3.0",
-      "resolved": "https://registry.npmjs.org/thenify/-/thenify-3.3.0.tgz",
-      "integrity": "sha1-5p44obq+lpsBCCB5eLn2K4hgSDk=",
-      "requires": {
-        "any-promise": "^1.0.0"
-      }
-    },
-    "thenify-all": {
-      "version": "1.6.0",
-      "resolved": "https://registry.npmjs.org/thenify-all/-/thenify-all-1.6.0.tgz",
-      "integrity": "sha1-GhkY1ALY/D+Y+/I02wvMjMEOlyY=",
-      "requires": {
-        "thenify": ">= 3.1.0 < 4"
-      }
-    },
     "timed-out": {
       "version": "4.0.1",
       "resolved": "https://registry.npmjs.org/timed-out/-/timed-out-4.0.1.tgz",