Bump Bazel version to 3.0.0

Change-Id: I1134cf4bb5f27d8e2f0bd3da02ef9c203c229629
diff --git a/.bazelversion b/.bazelversion
index ccbccc3..4a36342 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-2.2.0
+3.0.0