Adds Templates class and use it

This removes ugly hack when Plan class was used.
Templates retrieval was broken after Roles instantiation
inside of Plan was added b/c API did not returned any roles
in data when asked for templates.

Change-Id: I484dac7c41cb90256aa1dee3eb997a4183635591

tuskarclient/tests/v2/test_plans.py

@@ -125,7 +125,8 @@ class PlanManagerTest(tutils.TestCase):
         self.pm._get.return_value.to_dict.return_value = 'fake_templates_dict'
 
         self.assertEqual(self.pm.templates('fake_plan'), 'fake_templates_dict')
-        self.pm._get.assert_called_with('/v2/plans/fake_plan/templates')
+        self.pm._get.assert_called_with('/v2/plans/fake_plan/templates',
+                                        obj_class=plans.Templates)
 
     def test_roles_subresource(self):
         self.pm._get = mock.Mock(

tuskarclient/v2/plans.py

@@ -28,6 +28,15 @@ class Plan(common_base.Resource):
         self.roles = [roles.Role(None, role) for role in self.roles]
 
 
+class Templates(common_base.Resource):
+    """Represents sets of templates of a Plan in the Tuskar API.
+
+    :param manager: Manager object
+    :param info: dictionary representing resource attributes
+    :param loaded: prevent lazy-loading if set to True
+    """
+
+
 class PlanManager(base.Manager):
     """PlanManager interacts with the Tuskar API and provides CRUD
     operations for the Plan type.
@@ -157,7 +166,5 @@ class PlanManager(base.Manager):
         :rtype: dict
         """
 
-        # dirty hack as _get() will instantiate Plan with data
-        # coming from API response body
-        # and to_dict just get what we want
-        return self._get(self._templates_path(plan_uuid)).to_dict()
+        return self._get(self._templates_path(plan_uuid),
+                         obj_class=Templates).to_dict()