chore(package): update mocha to version 6.1.0

Author: greenkeeper[bot]

package.json

@@ -70,7 +70,7 @@
     "eslint-config-airbnb-base": "^13.1.0",
     "eslint-plugin-import": "^2.16.0",
     "istanbul": "^v1.1.0-alpha.1",
-    "mocha": "^5.0.4",
+    "mocha": "^6.1.0",
     "mochawesome": "^3.0.2",
     "nyc": "11.7.2",
     "ts-node": "8.0.3",