Cleanup py27 support

This repo is now testing only with Python 3, so let's make
a few cleanups:
- Remove obsolete sections from setup.cfg
- Update classifiers
- Cleanup doc/source/conf.py to remove now obsolete content.
- Use newer openstackdocstheme version

Change-Id: I2c59ca525fa329b91720149cff3faee00fafff97

doc/requirements.txt

@@ -2,6 +2,6 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.31.2 # Apache-2.0
 sphinx>=1.8.0,!=2.1.0 # BSD
 reno>=2.5.0 # Apache-2.0

doc/source/conf.py

@@ -65,8 +65,6 @@ pygments_style = 'sphinx'
 # html_static_path = ['static']
 html_theme = 'openstackdocs'
 
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
-
 # Output file base name for HTML help builder.
 htmlhelp_basename = '%sdoc' % project
 

releasenotes/source/conf.py

@@ -146,10 +146,6 @@ html_static_path = ['_static']
 # directly to the root of the documentation.
 # html_extra_path = []
 
-# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
-# using the given strftime format.
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
-
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
 # html_use_smartypants = True

setup.cfg

@@ -31,11 +31,6 @@ oslo.config.opts =
     oslo.service.sslutils = oslo_service.sslutils:list_opts
     oslo.service.wsgi = oslo_service.wsgi:list_opts
 
-[build_sphinx]
-warning-is-error = 1
-source-dir = doc/source
-build-dir = doc/build
-
 [upload_sphinx]
 upload-dir = doc/build/html