Added zenodo config file and self energy test

.zenodo.json

@@ -0,0 +1,24 @@
+{
+    "creators": [
+        {
+            "name": "Björn Stenqvist",
+            "affiliation": "Division of Physical Chemistry, Department of Chemistry, Lund University, Sweden",
+            "orcid": "0000-0002-9099-0663"
+        },
+        {
+            "name": "Mikael Lund",
+            "affiliation": "Division of Theoretical Chemistry, Department of Chemistry, Lund University, Sweden",
+            "orcid": "0000-0001-8178-8175"
+        }
+    ],
+    "keywords": [
+        "electrostatics",
+        "molecular dynamics",
+        "monte carlo",
+        "intermolecular interactions",
+        "multipoles",
+        "electric field"
+    ],
+    "license": "mit-license",
+    "upload_type": "software"
+}

test/unittests.cpp

@@ -662,6 +662,7 @@ TEST_CASE("[CoulombGalore] Splined") {
         CHECK(pot.short_range_function_second_derivative(0.5) == Approx(3.36159125).epsilon(tol));
         CHECK(pot.short_range_function_third_derivative(0.5) == Approx(-21.54779991).epsilon(tol));
         CHECK(pot.short_range_function(1.0) == Approx(0.0).epsilon(tol));
+        CHECK(pot.self_energy({4.0, 0.0}) == Approx( Wolf(alpha, cutoff).self_energy({4.0, 0.0}) ) );
     }
 
     SUBCASE("Poisson") {