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.

Disable openstackdocs_auto_name to use 'project' variable as name.

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.

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.

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

Change-Id: I9cad8904420d108a06d9fefbc2d3268738d56038

doc/requirements.txt

@@ -1,4 +1,4 @@
 # Even if we do not build doc with python 2, we have to
 # push that content due to some global check.
-sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2  # BSD
-openstackdocstheme>=1.20.0 # Apache-2.0
+sphinx>=2.0.0,!=2.1.0 # BSD
+openstackdocstheme>=2.2.1 # Apache-2.0

doc/source/conf.py

@@ -36,9 +36,9 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # openstackdocstheme options
-repository_name = 'openstack/paunch'
-bug_project = 'paunch'
-bug_tag = ''
+openstackdocs_repo_name = 'openstack/paunch'
+openstackdocs_bug_project = 'paunch'
+openstackdocs_bug_tag = ''
 
 # General information about the project.
 
@@ -52,7 +52,7 @@ add_function_parentheses = True
 add_module_names = True
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'sphinx'
+pygments_style = 'native'
 
 # -- Options for HTML output --------------------------------------------------
 

releasenotes/source/conf.py

@@ -97,7 +97,7 @@ 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 = []
@@ -113,9 +113,9 @@ pygments_style = 'sphinx'
 html_theme = 'openstackdocs'
 
 # openstackdocstheme options
-repository_name = 'openstack/paunch'
-bug_project = 'paunch'
-bug_tag = 'docs'
+openstackdocs_repo_name = 'openstack/paunch'
+openstackdocs_bug_project = 'paunch'
+openstackdocs_bug_tag = 'docs'
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the

test-requirements.txt

@@ -12,4 +12,4 @@ testscenarios>=0.4  # Apache-2.0/BSD
 testtools>=1.4.0 # MIT
 
 # releasenotes
-reno>=1.8.0 # Apache-2.0
+reno>=3.1.0 # Apache-2.0