Merge branch 'stable-3.1'

* stable-3.1:
  Upgrade bazlets to latest stable-3.0 to build with 3.0.7 API
  Upgrade bazlets to latest stable-2.16 to build with 2.16.16 API

Change-Id: I62534a29b60df821a6baa3a83f206b442d4263a3