Dependency on a problematic license

[jinwoo]

@google-cloud/common-grpc has a transitive dependency, jsonify, whose license is "Public Domain". "Public Domain" is not a valid license for Google.

This issue blocks #2785.

We need to either get an approval for that package or remove the dependency.

The dependency chain is like this:

@google-cloud/common-grpc@0.5.2 -> grpc@1.7.3 -> node-pre-gyp@0.6.39 -> request@2.81.0 -> har-validator@4.2.1 -> ajv@4.11.8 -> json-stable-stringify@1.0.1 -> jsonify@0.0.0

[jinwoo]

I made a PR in the node-pre-gyp package as a resolution to this: mapbox/node-pre-gyp#342

But that makes tests fail with Node 0.10.

[jinwoo]

Closing this because an issue was filed directly under grpc: grpc/grpc-node#145