Add a gate setup script

This patch set adds in a skeleton setup_gate.sh script in preparation
of integration with the OpenStack infra job.

Change-Id: I62e84593e50b5e5d8ee04007d5e36cd3116322d8

tools/gate/setup_gate.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -ex
+
+#TODO(lamt) Need to replace with actual gate logic.  Placeholder for now.
+env
+exit 0