Switch to newer openstackdocstheme and reno versions

Switch to openstackdocstheme 2.2.1 and reno 3.1.0 versions. Using
these versions will allow especially:
* Linking from HTML to PDF document
* Allow parallel building of documents
* Fix some rendering problems

Update Sphinx version as well.

Remove docs requirements from lower-constraints, they are not needed
during install or test but only for docs building.

openstackdocstheme renames some variables, so follow the renames
before the next release removes them. A couple of variables are also
not needed anymore, remove them.

Set openstackdocs_pdf_link to link to PDF file. Note that
the link to the published document only works on docs.openstack.org
where the PDF file is placed in the top-level html directory. The
site-preview places the PDF in a pdf directory.

Change pygments_style to 'native' since old theme version always used
'native' and the theme now respects the setting and using 'sphinx' can
lead to some strange rendering.

See also
http://lists.openstack.org/pipermail/openstack-discuss/2020-May/014971.html

Change-Id: I4af25bbc8d990aa5e70ee63ba7477d2964872b3f

doc/requirements.txt

@@ -1,7 +1,7 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
-sphinx>=1.8.0,!=2.1.0  # BSD
+sphinx>=2.0.0,!=2.1.0 # BSD
 sphinxcontrib-svg2pdfconverter>=0.1.0 # BSD
-openstackdocstheme>=1.30.0 # Apache-2.0
-reno>=2.5.0 # Apache-2.0
+openstackdocstheme>=2.2.1 # Apache-2.0
+reno>=3.1.0 # Apache-2.0

doc/source/conf.py

@@ -50,7 +50,7 @@ add_function_parentheses = True
 add_module_names = True
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'sphinx'
+pygments_style = 'native'
 
 suppress_warnings = ['image.nonlocal_uri']
 
@@ -79,9 +79,10 @@ latex_documents = [
 latex_elements = {'maxlistdepth': 10, 'extraclassoptions': ',openany,oneside'}
 
 # openstackdocstheme options
-repository_name = 'openstack/python-tripleoclient'
-bug_project = 'python-tripleoclient'
-bug_tag = ''
+openstackdocs_repo_name = 'openstack/python-tripleoclient'
+openstackdocs_pdf_link = True
+openstackdocs_bug_project = 'python-tripleoclient'
+openstackdocs_bug_tag = ''
 
 # Last updated timestamp
 autoprogram_cliff_application = 'openstack'

lower-constraints.txt

@@ -134,7 +134,6 @@ simplegeneric==0.8.1
 simplejson==3.5.1
 six==1.10.0
 smmap==0.9.0
-Sphinx==1.6.2
 sqlalchemy-migrate==0.11.0
 SQLAlchemy==1.0.10
 sqlparse==0.2.2

releasenotes/source/conf.py

@@ -87,7 +87,7 @@ exclude_patterns = []
 #show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'sphinx'
+pygments_style = 'native'
 
 # A list of ignored prefixes for module index sorting.
 #modindex_common_prefix = []