Merge branch 'stable-3.1'

* stable-3.1:
  Bump Bazel version to 3.0.0

Change-Id: Iaa9904b08b0007b5d25a6a2f8b43044112b99232
diff --git a/.bazelversion b/.bazelversion
index ccbccc3..4a36342 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-2.2.0
+3.0.0