Fix for now-allowed PATCH on users

Commit 0f0a4be4 introduced using PATCH on users to set the username.
An old unit test failed, as it checks that PATCH is not allowed (e.g.
tests for 405 Method Not Allowed response).

tests/test_api/test_auth.py

@@ -187,16 +187,6 @@ class AuthenticationTests(AbstractPillarTest):
         db_user = fetch_user()
         self.assertEqual(['subscriber'], db_user['roles'])
 
-        # PATCH should not be allowed.
-        updated_fields = {'roles': ['admin', 'subscriber', 'demo']}
-        self.patch('/api/users/%s' % user_id,
-                   json=updated_fields,
-                   auth_token='token',
-                   etag=db_user['_etag'],
-                   expected_status=405)
-        db_user = fetch_user()
-        self.assertEqual(['subscriber'], db_user['roles'])
-
     def test_token_expiry(self):
         """Expired tokens should be deleted from the database."""