fixed several pep8 issues

  * E113 unexpected indentation
  * E121 continuation line under-indented for hanging indent
  * E122 continuation line missing indentation or outdented
  * E251 unexpected spaces around keyword / parameter equals
  * E265 block comment should start with '# '
  * E713 test for membership should be 'not in'
  * E714 test for object identity should be 'is not'

Also changed used pep8 version in test-requirements to
8==1.4.6,==1.5.6.

Change-Id: If39da01db5dfae81e7702902b5fe1d5a0224bb19