Added goal filter in Watcher API

Although it was proposed via python-watcherclient, the feature was
not implemented on the Watcher API.
As the notion of host aggregate is currently unused in Watcher,
decision was made to only implement the filtering of goal within
the Watcher API whilst removing the host_aggregate filter from the
Watcher client.
Thus, this patchset adds this missing functionality by adding the
'goal' parameter to the API.

Change-Id: I54d248f7e470249c6412650ddf50a3e3631d2a09
Related-Bug: #1510189

watcher/tests/api/v1/test_audit_templates.py

@@ -207,6 +207,25 @@ class TestListAuditTemplate(api_base.FunctionalTest):
         next_marker = response['audit_templates'][-1]['uuid']
         self.assertIn(next_marker, response['next'])
 
+    def test_filter_by_goal(self):
+        cfg.CONF.set_override('goals', {"DUMMY": "DUMMY", "BASIC": "BASIC"},
+                              group='watcher_goals', enforce_type=True)
+
+        for id_ in range(2):
+            obj_utils.create_test_audit_template(
+                self.context, id=id_, uuid=utils.generate_uuid(),
+                name='My Audit Template {0}'.format(id_),
+                goal="DUMMY")
+
+        for id_ in range(2, 5):
+            obj_utils.create_test_audit_template(
+                self.context, id=id_, uuid=utils.generate_uuid(),
+                name='My Audit Template {0}'.format(id_),
+                goal="BASIC")
+
+        response = self.get_json('/audit_templates?goal=BASIC')
+        self.assertEqual(3, len(response['audit_templates']))
+
 
 class TestPatch(api_base.FunctionalTest):