chore(package): update mocha to version 7.1.1

Closes #31

Author: greenkeeper[bot]

package.json

@@ -34,7 +34,7 @@
     "eslint": "^5.7.0",
     "eslint-plugin-prefer-let": "^1.0.1",
     "expect": "^24.1.0",
-    "mocha": "^6.0.0",
+    "mocha": "^7.1.1",
     "nyc": "^13.1.0",
     "rollup": "^1.0.0",
     "rollup-plugin-babel": "^4.2.0",