update @google-cloud/common-grpc deps

Author: stephenplusplus

package.json

@@ -34,7 +34,7 @@
   ],
   "dependencies": {
     "@google-cloud/common": "^0.12.0",
-    "@google-cloud/common-grpc": "^0.2.0",
+    "@google-cloud/common-grpc": "^0.2.1",
     "arrify": "^1.0.1",
     "checkpoint-stream": "^0.1.0",
     "events-intercept": "^2.0.0",