Enable PEP8 checks H102, H232, H233, H301, H904

* H102  Apache 2.0 license header not found
* H232  Python 3.x incompatible octal xxx should be written as 0oxxx
* H233  Python 3.x incompatible use of print operator
* H301  one import per line
* H904  Wrap long lines in parentheses instead of a backslash

Change-Id: I07003acb76eaa719daabc451239067494efa2bba

packstack/version.py

@@ -1,4 +1,16 @@
 # -*- 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 os
 import pkg_resources