[GCE] Google Cloud Pubsub Module (#19091)

* Google Cloud Pubsub Module

The Google Cloud Pubsub module allows the Ansible user to:
* Create/Delete Topics
* Create/Delete Subscriptions
* Change subscription from pull to push (and configure endpoint)
* Publish messages to a topic
* Pull messages from a Subscription

An accessory module, gcpubsub_facts, has been added to list topics and subscriptions.

* Added docs for state field to DOCUMENTATION and RETURN blocks.

test/units/module_utils/gcp/test_utils.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# (c) 2016, Tom Melendez <tom@supertom.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+import os
+import sys
+
+from ansible.compat.tests import mock, unittest
+from ansible.module_utils.gcp import (check_min_pkg_version)
+
+def build_distribution(version):
+    obj = mock.MagicMock()
+    obj.version = '0.5.0'
+    return obj
+
+
+class GCPUtilsTestCase(unittest.TestCase):
+
+    @mock.patch("pkg_resources.get_distribution", side_effect=build_distribution)
+    def test_check_minimum_pkg_version(self, mockobj):
+        self.assertTrue(check_min_pkg_version('foobar', '0.4.0'))
+        self.assertTrue(check_min_pkg_version('foobar', '0.5.0'))
+        self.assertFalse(check_min_pkg_version('foobar', '0.6.0'))
+
+
+if __name__ == '__main__':
+    unittest.main()