Merge branch 'stable-3.0'

* stable-3.0:
  Replace bazel-genfiles with bazel-bin in documentation
  Upgrade bazlets to latest stable-3.0 to build with 3.0.3 API
  Bump bazel version to 1.0.0
  Add PolyGerrit UI for configuring uploadvalidator
  Upgrade bazlets to latest stable-2.16 to build with 2.16.12 API
  Upgrade bazlets to latest stable-2.15 to build with 2.15.17 API

Change-Id: I3ecff8a2a67826addcbc2e2e8622541cd9cc39df