Bump Bazel version to 2.0.0

Change-Id: Ica0d92699aa6ce2c44ef3693cf0652ceb28c7905
diff --git a/.bazelversion b/.bazelversion
index 9084fa2..227cea2 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-1.1.0
+2.0.0