fix(package): update @google-cloud/common to version 0.16.0 (#394)

Author: greenkeeper[bot]

package.json

@@ -62,7 +62,7 @@
  "typescript": "~2.6.1"
  },
  "dependencies": {
- "@google-cloud/common": "^0.15.1",
+ "@google-cloud/common": "^0.16.0",
  "acorn": "^5.0.3",
  "async": "^2.1.2",
  "coffee-script": "^1.9.3",