Bump openstackdocstheme to 1.20.0

Some options are now automatically configured by the version 1.20:
- project
- html_last_updated_fmt
- latex_engine
- latex_elements
- version
- release.

Change-Id: Icbfa21da1e83f745a98822a2f33c4ebc8d11fd0c

doc/requirements.txt

@@ -2,7 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 # These are needed for docs generation
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.20.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0
 sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7' # BSD
 sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4' # BSD

doc/source/conf.py

@@ -14,7 +14,7 @@
 
 import os
 import sys
-import pbr.version
+import openstackdocstheme
 
 sys.setrecursionlimit(4000)
 
@@ -48,17 +48,12 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = 'python-cinderclient'
 copyright = 'OpenStack Contributors'
 
-# The version info for the project you're documenting, acts as replacement for
-# |version| and |release|, also used in various other places throughout the
-# built documents.
-version_info = pbr.version.VersionInfo('python-cinderclient')
-# The short X.Y version.
-version = version_info.version_string()
-# The full version, including alpha/beta/rc tags.
-release = version_info.release_string()
+# done by the openstackdocstheme ext
+# project = 'python-cinderclient'
+# version = version_info.version_string()
+# release = version_info.release_string()
 
 # List of directories, relative to source directory, that shouldn't be searched
 # for source files.
@@ -84,7 +79,7 @@ html_theme = 'openstackdocs'
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
 # html_last_updated_fmt = '%b %d, %Y'
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
+# html_last_updated_fmt = '%Y-%m-%d %H:%M'
 
 # -- Options for manual page output ------------------------------------------