Merge branch 'stable-3.0'

* stable-3.0:
  Upgrade bazlets to latest stable-3.0
  Upgrade bazlets to latest stable-2.16
  Upgrade bazlets to latest stable-2.15
  Bump required bazel version to 1.0.0rc2
  Upgrade bazlets to latest stable-2.14
  Upgrade bazlets to latest stable-2.15
  Upgrade bazlets to latest stable-2.14

Change-Id: Ic070017d05ce620e03799ddac8d1a05ee3a86050