Fix PEP8 Issues in Shipyard

This patch cleans up docs/*.py and update tox.ini's exclude target
as well as specifying pep8 to scan *.py files only.

Change-Id: Ic81cc81edd9da682581d9deb0a7a5404bb7aa4d9

docs/source/conf.py

@@ -19,6 +19,7 @@
 # import os
 # import sys
 # sys.path.insert(0, os.path.abspath('.'))
+import sphinx_rtd_theme
 
 
 # -- General configuration ------------------------------------------------
@@ -96,7 +97,6 @@ todo_include_todos = False
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-import sphinx_rtd_theme
 html_theme = "sphinx_rtd_theme"
 html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
@@ -165,6 +165,7 @@ man_pages = [
 texinfo_documents = [
     (master_doc, 'Shipyard', u'Shipyard Documentation',
      author, 'Shipyard',
-     'Directed acyclic graph controller for Kubernetes and OpenStack CP life-cycle management.',
+     'Directed acyclic graph controller for Kubernetes'
+     ' and OpenStack CP life-cycle management.',
      'Miscellaneous'),
 ]

tox.ini

@@ -25,13 +25,14 @@ commands = oslo-config-generator --config-file=generator/config-generator.conf
 commands = oslopolicy-sample-generator --config-file=generator/policy-generator.conf
 
 [flake8]
+filename = *.py
 # NOTE(Bryan Strassner) ignoring F841 because of the airflow example pattern
 #     of naming variables even if they aren't used for DAGs and Operators.
 #     Doing so adds readability and context in this case.
 ignore = F841
 # NOTE(Bryan Strassner) excluding 3rd party and generated code that is brought into the
 #     codebase.
-exclude = *plugins/rest_api_plugin.py,*lib/python*,*egg,.git*,*.md,.tox*,alembic/env.py,build/*
+exclude = .venv,.git,.tox,build,dist,*plugins/rest_api_plugin.py,*lib/python*,*egg,alembic/env.py,docs
 
 [testenv:docs]
 whitelist_externals=rm