chore(deps): update dependency nyc to v14 (#356)

Author: renovate[bot]

packages/google-cloud-vision/package.json

@@ -60,7 +60,7 @@
     "intelli-espower-loader": "^1.0.1",
     "jsdoc": "^3.5.5",
     "mocha": "^6.0.0",
-    "nyc": "^13.0.0",
+    "nyc": "^14.0.0",
     "power-assert": "^1.6.0",
     "prettier": "^1.13.6",
     "sinon": "^7.0.0",