A plain `grep` was occasionally attempting to grep temporaary files that
were being created and deleted concurrently by other sanity check
scripts, leading to TOCTOU problems. This now only searches indexed
files (thanks for the suggestion, @ctiller!).
We still need to exclude `third_party` since upb is not a submodule.
`git grep` will ignore all submodules by default, so the other
third_party subfolders were already excluded.
* Add grpcio-csds pacakge
* Remove unused file
* Fix the proto import path issue
* Update the CSDS package and xds-protos for PY2
* Make tests happy
* Fix Bazel proto dependency
* Add Python2 tests for CSDS
- add rubocop as a dev dependency
- fixed many style violations it reported, often using --auto-correct
- add a rubocop config
- .rubocop.yml shows the exceptions
- .rubocopy_todo.yml tracks outstanding style issues
- adds a rake task to allow rubocop styling checks to be automated