Build with stable version

Now that 3.3.0 stable version is out, build with it instead of
the snapshot (which only pulls from local repository). Also,
update the bazelets to 3.3.0 to fix failing compilation with
3.2. Since we aren't specifying any version it is directly
inferred from the bazelts commit.

Change-Id: I01596e41bbfecfec02331ff2b0a27755a3c1f773

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 2450121..879bcff 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -12,4 +12,6 @@
     "gerrit_api",
 )
 
-gerrit_api(version = "3.3.0-SNAPSHOT")
+# specify version with `-SNAPSHOT` prefix to pull from local repo
+# example: gerrit_api(version = "3.3.0-SNAPSHOT")
+gerrit_api()