chore(package): update mocha to version 7.2.0

Closes #18

Author: greenkeeper[bot]

package.json

@@ -43,7 +43,7 @@
     "chai": "^4.1.2",
     "chai-as-promised": "^7.1.1",
     "codecov": "^3.0.2",
-    "mocha": "^5.2.0",
+    "mocha": "^7.2.0",
     "np": "^3.0.1",
     "nyc": "^12.0.1",
     "prettier": "^1.13.3",