fix(deps): update dependency @google-cloud/common to v3 (#561)

Author: renovate-bot

packages/google-cloud-speech/package.json

@@ -43,7 +43,7 @@
     "prelint": "cd samples; npm link ../; npm i"
   },
   "dependencies": {
-    "@google-cloud/common": "^2.0.0",
+    "@google-cloud/common": "^3.0.0",
     "google-gax": "^2.0.1",
     "protobufjs": "^6.8.6",
     "pumpify": "^2.0.0",