carto/protobuf @ revert-6128-convert-to-ruby

Keith Smiley 1958925c76 Add -Werror for CI builds		6 éve
..
linux	1958925c76 Add -Werror for CI builds	6 éve
macos	077079573f Fixed CI failures with Ruby 2.3 on OSX (#5948)	6 éve
release	67fee07308 C#: set some dotnet options when testing	6 éve
windows	36fa3c6d4d add missing C# windows presubmit.cfg file (#5894)	6 éve
README.md	6156af10e8 Add MacOS and Linux tests to Kokoro	8 éve

Kokoro Infrastructure

The files in this directory serve as plumbing for running Protobuf tests under Kokoro, our internal CI.