* Use Bazel to build the entire backend.
This also uses Bazel to generate code from the API definition in the
proto files.
The Makefile is replaced with a script that uses Bazel to first generate
the code, and then copy them back into the source tree.
Most of the BUILD files were generated automatically using Gazelle.
* Fix indentation in generate_api.sh
* Clean up WORKSPACE
* Add README for building/testing backend.
Also fix the missing licenses in the generated proto files.
* Add license to files under go_http_client
Ajay Gopinathan