Merge branch 'stable-3.0'

* stable-3.0:
  Bump Bazel version to 2.2.0

Change-Id: Idb1ef0010c00f3c42242802a34393a30db501773
diff --git a/.bazelversion b/.bazelversion
index 7ec1d6d..ccbccc3 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-2.1.0
+2.2.0