chore(package): update mocha to version 7.1.0

Closes #58

Author: greenkeeper[bot]

package.json

@@ -32,7 +32,7 @@
     "babel-preset-env": "^1.7.0",
     "babel-register": "^6.26.0",
     "chai": "^4.2.0",
-    "mocha": "^6.1.4",
+    "mocha": "^7.1.0",
     "pre-commit": "^1.2.2",
     "sinon": "^7.3.2",
     "smtp-server": "^3.5.0",