Merge branch 'stable-3.0'

* stable-3.0:
  Bump required Bazel version to 2.1.0

Change-Id: I1d2d0bbb8f013167e88b9efcae30b5a396f5b4b8

.bazelversion

diff --git a/.bazelversion b/.bazelversion
index 227cea2..7ec1d6d 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-2.0.0
+2.1.0