Fix build pipeline

.github/workflows/build.yml

@@ -6,15 +6,15 @@ jobs:
   build:
     services:
       mongodb:
-        image: mongo:3.4.23
+        image: mongo:4.2
         ports:
           - 27017:27017
       redis:
         image: redis
         ports:
           - 6379:6379
 
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     env:
       GO111MODULE: on
@@ -23,14 +23,11 @@ jobs:
     - name: Install Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.15
+        go-version: 1.16
 
     - name: Get tyk from source repository
       uses: actions/checkout@v2
 
-    - name: Install dependencies
-      run: go get golang.org/x/tools/cmd/goimports && go get
-
     - name: Run tests
       run: go test -v ./...