chore(package): update mocha to version 7.1.0

Closes #61

Author: greenkeeper[bot]

package.json

@@ -41,7 +41,7 @@
         "chai": "^4.2.0",
         "del": "^5.1.0",
         "husky": "^3.0.9",
-        "mocha": "^6.2.2",
+        "mocha": "^7.1.0",
         "prettier": "^1.18.2",
         "pretty-quick": "^2.0.0",
         "sinon": "^7.5.0",