Expose what's happening behind the scenes for test_user_if_present_with_gid()

* Expose what's happening in `integration.states.user.UserTest.test_user_if_present_with_gid()`.
* Update code that was using the old `SaltReturnAssertsMixIn`.

tests/integration/states/user.py

@@ -10,7 +10,8 @@ import integration
 import grp
 
 
-class UserTest(integration.ModuleCase):
+class UserTest(integration.ModuleCase,
+               integration.SaltReturnAssertsMixIn):
     '''
     test for user absent
     '''
@@ -27,8 +28,7 @@ class UserTest(integration.ModuleCase):
     def test_user_if_present_with_gid(self):
         # TODO:dc fix failing test. Exception in ret
         ret = self.run_state('user.present', name='nobody', gid="nobody")
-        result = ret[next(iter(ret))]['result']
-        self.assertTrue(result)
+        self.assertSaltTrueReturn(ret)
 
     @destructiveTest
     @skipIf(os.geteuid() is not 0, 'you must be this root to run this test')

tests/integration/states/virtualenv.py

@@ -35,10 +35,7 @@ class VirtualenvTest(integration.ModuleCase,
             ret = self.run_function(
                 'state.sls', mods='issue-1959-virtualenv-runas'
             )
-            self.assertTrue(isinstance(ret, dict))
-            self.assertNotEqual(ret, {})
-            for part in ret.itervalues():
-                self.assertSaltTrueReturn(part)
+            self.assertSaltTrueReturn(ret)
 
             # Lets check proper ownership
             statinfo = self.run_function('file.stats', [venv_dir])