test: ensure clientv3 has no grpc-gateway dependency

test

@@ -333,8 +333,8 @@ function dep_pass {
 	echo "Checking package dependencies..."
 	# don't pull in etcdserver package
 	pushd clientv3 >/dev/null
-	badpkg="(etcdserver|mvcc)"
-	deps=`go list -f '{{ .Deps }}'  | sed 's/ /\n/g' | egrep "${badpkg}" | egrep -v "${badpkg}/" || echo ""`
+	badpkg="(etcdserver$|mvcc$|backend$|grpc-gateway)"
+	deps=`go list -f '{{ .Deps }}'  | sed 's/ /\n/g' | egrep "${badpkg}" || echo ""`
 	popd >/dev/null
 	if [ ! -z "$deps" ]; then
 		echo -e "clientv3 has masked dependencies:\n${deps}"