Renamed Status to State

As we can see in the codebase, we have 3 "Status" enums which are
located at:

- watcher/objects/action.py
- watcher/objects/action_plan.py
- watcher/objects/audit.py

So I renamed them from "Status" to "State" to be consistent with
the DB schema.

Change-Id: If3d180c9daba6ae9083775ad6813aa4c21763dbf
Closes-Bug: #1522733

watcher/tests/api/v1/test_audits.py

@@ -443,7 +443,7 @@ class TestPost(api_base.FunctionalTest):
         self.assertEqual(urlparse.urlparse(response.location).path,
                          expected_location)
         self.assertEqual(audit_dict['uuid'], response.json['uuid'])
-        self.assertEqual(objects.audit.AuditStatus.PENDING,
+        self.assertEqual(objects.audit.State.PENDING,
                          response.json['state'])
         self.assertNotIn('updated_at', response.json.keys)
         self.assertNotIn('deleted_at', response.json.keys)
@@ -492,7 +492,7 @@ class TestPost(api_base.FunctionalTest):
         response = self.post_json('/audits', audit_dict)
         self.assertEqual('application/json', response.content_type)
         self.assertEqual(201, response.status_int)
-        self.assertEqual(objects.audit.AuditStatus.PENDING,
+        self.assertEqual(objects.audit.State.PENDING,
                          response.json['state'])
         self.assertTrue(utils.is_uuid_like(response.json['uuid']))