message: chore(package): update mocha to version 5.2.0
  Closes
diff: "esprima-fb": "^15001.1001.0-dev-harmony-fb",
  "flow-parser": "^0.68.0",
  "glob": "^7.1.2",
  - "mocha": "~5.0.0",
  - "reify": "^0.16.2"
  + "mocha": "~5.2.0",
  + "reify": "^0.16.4"
  },
  "engines": {
  "node": ">= 4"
  