build: create docs test npm scripts (#166)

Author: JustinBeckwith

packages/google-cloud-bigquery-datatransfer/package.json

@@ -34,7 +34,9 @@
     "lint": "eslint '**/*.js'",
     "docs": "jsdoc -c .jsdoc.js",
     "system-test": "mocha system-test/*.js smoke-test/*.js --timeout 600000",
-    "fix": "eslint --fix '**/*.js'"
+    "fix": "eslint --fix '**/*.js'",
+    "docs-test": "blcl docs -r --exclude www.googleapis.com",
+    "predocs-test": "npm run docs"
   },
   "dependencies": {
     "google-gax": "^0.25.0",
@@ -53,6 +55,7 @@
     "mocha": "^5.2.0",
     "nyc": "^13.0.0",
     "power-assert": "^1.5.0",
-    "prettier": "^1.13.4"
+    "prettier": "^1.13.4",
+    "broken-link-checker-local": "^0.2.0"
   }
 }