chore(package): update mocha to version 6.0.1

Closes #45

Author: greenkeeper[bot]

package.json

@@ -53,7 +53,7 @@
     "karma-mocha": "^1.3.0",
     "karma-sourcemap-loader": "^0.3.7",
     "karma-webpack": "^3.0.0",
-    "mocha": "^5.0.0",
+    "mocha": "^6.0.1",
     "pouchdb-find": "^6.4.2",
     "pouchdb-memory": "^6.0.0",
     "sinon": "^6.0.1",