chore(jest): fix coverage reports

mapping seemed faulty and completly uncovered files are now being picked up

Author: Xiphe

package.json

@@ -28,7 +28,12 @@
     "transform": {
       "^.+\\.jsx?$": "babel-jest"
     },
-    "mapCoverage": true,
+    "collectCoverageFrom": [
+      "**/*.{js,jsx}",
+      "!node_modules/**",
+      "!coverage/**",
+      "!index.js"
+    ],
     "coverageThreshold": {
       "global": {
         "branches": 100,