message: Downgrade gRPC to ~1.7
  GoogleCloudPlatform/google-cloud-node#2784
  grpc/grpc-node#130
  googleapis/nodejs-datastore#35
diff: "google-auto-auth": "^0.9.0",
  "google-gax": "^0.14.2",
  "google-proto-files": "^0.14.1",
  - "grpc": "^1.7.2",
  + "grpc": "~1.7.2",
  "is": "^3.0.1",
  "lodash.merge": "^4.6.0",
  "lodash.snakecase": "^4.1.1",
  