Add version.py file to be able to figure out the active version

ChangeLog

@@ -1,5 +1,7 @@
 0.10:
   - Add LICENSE in generated source tarballs
+  - Add a version.py file that can be used to
+    extract the current version.
 0.9:
   - Allow providing a non-standard (eventlet or
     other condition class) to the r/w lock for

fasteners/version.py

@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (C) 2014 Yahoo! Inc. All Rights Reserved.
+# Copyright 2011 OpenStack Foundation.
+#
+# All Rights Reserved.
+#
+#    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.
+
+_VERSION = "0.10"
+
+
+def version_string():
+    return _VERSION