deprecate the entire library

the library is essentially unmaintained, no tests have been added
since it's inception 1.5 years ago.

we can move the functionality to django_openstack_auth proper
using extras, or attic the entire library if no one is using it.
either way, this is a step toward both of those outcomes.

Change-Id: I5e2cf2852e89586415ddbe8da022f7461b3ba0d6
Closes-Bug: 1584432

openstack_auth_kerberos/__init__.py

@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import warnings
+
+
+warnings.warn(
+    "The openstack_auth_kerberos package is deprecated in favor of "
+    "authenticating with kerberos through federation, this library will "
+    "no longer be supported.",
+    DeprecationWarning)