Switch to newer openstackdocstheme versions

Switch to openstackdocstheme 2.2.1 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.

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: I3600b36580b01bd122d84dc14316b94f6c2ee78f

doc/source/conf.py

@@ -11,10 +11,10 @@ sys.path.insert(0, os.path.abspath('../..'))
 extensions = ['sphinx.ext.autodoc', 'openstackdocstheme']
 
 # openstackdocstheme options
-repository_name = 'openstack/mox3'
-bug_project = ''
-bug_tag = ''
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
+openstackdocs_repo_name = 'openstack/mox3'
+openstackdocs_bug_project = 'python-mox3'
+openstackdocs_auto_name = False
+openstackdocs_bug_tag = ''
 
 # autodoc generation is a bit aggressive and a nuisance when doing heavy
 # text edit cycles.
@@ -41,7 +41,7 @@ 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 --------------------------------------------------
 

test-requirements.txt

@@ -11,6 +11,6 @@ testtools>=2.2.0 # MIT
 six>=1.10.0 # MIT
 
 # this is required for the docs build jobs
-sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.5 # BSD
-openstackdocstheme>=1.18.1 # Apache-2.0
+sphinx>=2.2.0,!=2.1.0 # BSD
+openstackdocstheme>=2.2.1 # Apache-2.0