chore(package): update mocha to version 7.1.2

Closes #117

Author: greenkeeper[bot]

package.json

@@ -28,7 +28,7 @@
     "sprintf-js": "^1.1.2"
   },
   "devDependencies": {
-    "mocha": "^6.1.4",
+    "mocha": "^7.1.2",
     "chai": "^4.2.0",
     "chai-as-promised": "^7.1.1",
     "sinon": "^7.3.2",