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: Iac415cd5bd7346847edeb174b059ffbc3e2a1bdf

doc/source/conf.py

@@ -35,7 +35,7 @@ extensions = ['sphinx.ext.autodoc',
              ]
 
 # Feed configuration for yasfb
-feed_base_url = 'http://specs.openstack.org/openstack/barbican-specs'
+feed_base_url = 'https://specs.openstack.org/openstack/barbican-specs'
 feed_author = 'OpenStack Barbican Team'
 
 todo_include_todos = True
@@ -89,11 +89,17 @@ add_module_names = False
 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 = ['barbican-specs.']
 
+# openstackdocstheme options
+openstackdocs_repo_name = 'openstack/barbican-specs'
+openstackdocs_auto_name = False
+openstackdocs_bug_project = 'barbican'
+openstackdocs_bug_tag = ''
+
 # -- Options for man page output ----------------------------------------------
 man_pages = []
 

requirements.txt

@@ -1,5 +1,5 @@
-openstackdocstheme>=1.32.1
-sphinx!=2.1.0,>=2.0.0
+openstackdocstheme>=2.2.1 # Apache-2.0
+sphinx>=2.0.0,!=2.1.0 # BSD
 stestr>2.0.0 # Apache-2.0
 testtools>=0.9.34
 yasfb>=0.8.0