Use taskflow library for building and executing action plans

The aim of this patchset is to integrate taskflow in
the Watcher Applier. Taskflow will help us a lot to make
Action Plan execution easy, consistent, scalable and reliable.

DocImpact

Partially implements: blueprint use-taskflow

Change-Id: I903d6509d74a61ad64e1506b8a7156e6e91abcfb
Closes-Bug: #1535326
Closes-Bug: #1531912

watcher/tests/applier/messaging/test_trigger_action_plan_endpoint.py

@@ -0,0 +1,41 @@
+# -*- encoding: utf-8 -*-
+# Copyright (c) 2015 b<>com
+#
+# Authors: Jean-Emile DARTOIS <jean-emile.dartois@b-com.com>
+#
+# 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.
+#
+
+
+import mock
+
+from watcher.applier.messaging import trigger
+from watcher.common import utils
+from watcher.tests import base
+
+
+class TestTriggerActionPlan(base.TestCase):
+    def __init__(self, *args, **kwds):
+        super(TestTriggerActionPlan, self).__init__(*args, **kwds)
+        self.applier = mock.MagicMock()
+        self.endpoint = trigger.TriggerActionPlan(self.applier)
+
+    def setUp(self):
+        super(TestTriggerActionPlan, self).setUp()
+
+    def test_launch_action_plan(self):
+        action_plan_uuid = utils.generate_uuid()
+        expected_uuid = self.endpoint.launch_action_plan(self.context,
+                                                         action_plan_uuid)
+        self.assertEqual(action_plan_uuid, expected_uuid)