feat(cloudbuild): generate v1

[busunkim96]

I named the directory cloudbuild rather than build.

The generator names the package google-cloud-cloudbuild, but I'd be open to naming it google-cloud-build. Thoughts?

Product team said they preferred google-cloud-build, so I've added a synth replace.

TODO:

• Setup Kokoro configs internally
• Add Kokoro config in GitHub

[tseaver]

The only other library (containeranalysis) which uses google/cloud/devtools doesn't declare it as a namespace package, which means that installing it won't be compatible with this one if we continue to ship the library this PR generates.

[busunkim96]

I thinkgoogle/cloud/ is the only namespace package for both?

google/cloud/__init__.py (namespace package):

• containeranalysis/google/cloud/__init__.py
• cloudbuild/google/cloud/__init__.py

google/cloud/devtools/__init__.py (regular package):

• containeranalysis/google/cloud/devtools/__init__.py
• cloudbuild/google/cloud/devtools/__init__.py

[tseaver]

@busunkim96 Try installing google-cloud-containeranalysis and the new google-cloud-build library in the same virtualenv: the fact that google.cloud.devtools is not declared by both as a namespace package means that one of the two won't be importable (or maybe the second install will fail, depending on pip's behavior).

[busunkim96]

@tseaver Ah I see. So my options are:

1. change containeranalysis and cloudbuild to both declare google.cloud.devtools as a namespace package.
2. place cloudbuild in google.cloud.cloudbuild

I'll probably do 1, and note in the README that you need google-cloud-containeranalysis>=x.x.x to be able to install side by side with google-cloud-build.