Update gerrit-api version to 3.4.0-SNAPSHOT

Change-Id: Ibed78195a076d70e99129a9861a7f605b4f2ea06
diff --git a/WORKSPACE b/WORKSPACE
index bd2bc1a..1324968 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -12,7 +12,7 @@
     "gerrit_api",
 )
 
-gerrit_api(version = "3.3.0-SNAPSHOT")
+gerrit_api(version = "3.4.0-SNAPSHOT")
 
 load("//:external_plugin_deps.bzl", "external_plugin_deps")