fix(package): update mocha to version 7.1.2

Closes #2

Author: greenkeeper[bot]

package.json

@@ -13,7 +13,7 @@
   "license": "MIT",
   "dependencies": {
     "chai": "^4.1.2",
-    "mocha": "^4.0.1",
+    "mocha": "^7.1.2",
     "nyc": "^11.2.1"
   },
   "devDependencies": {