Restructure tests into more appropriate files

- Restructuring tests into more appropriate files (removing `test.requests.js` which was very generic)
- Fixed an issue with parsing certain URLs in admin/directory_v1 API and pubsub v1beta1 API paths
- Add JSDoc documentation metadata to templates
- Add migration guide
- Update README to flow better from step to step
- Add options documentation to README
Maybe we should say their readable stream may be unstable.