Bump the openstackdocstheme extension to 1.20

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

Change-Id: Ia656e992e86293339521627acc892f81f7bd6a0b

doc/source/conf.py

@@ -67,9 +67,6 @@ repository_name = 'openstack/tempest'
 bug_project = 'tempest'
 bug_tag = 'doc'
 
-# Must set this variable to include year, month, day, hours, and minutes.
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
-
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
 
@@ -83,7 +80,6 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'Tempest'
 copyright = u'2013, OpenStack QA Team'
 
 # The language for content autogenerated by Sphinx. Refer to documentation

releasenotes/source/conf.py

@@ -46,9 +46,6 @@ repository_name = 'openstack/tempest'
 bug_project = 'tempest'
 bug_tag = ''
 
-# Must set this variable to include year, month, day, hours, and minutes.
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
-
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
 
@@ -62,7 +59,6 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'tempest Release Notes'
 copyright = u'2016, tempest Developers'
 
 # Release do not need a version number in the title, they
@@ -193,17 +189,6 @@ htmlhelp_basename = 'tempestReleaseNotesdoc'
 
 # -- Options for LaTeX output ---------------------------------------------
 
-latex_elements = {
-    # The paper size ('letterpaper' or 'a4paper').
-    # 'papersize': 'letterpaper',
-
-    # The font size ('10pt', '11pt' or '12pt').
-    # 'pointsize': '10pt',
-
-    # Additional stuff for the LaTeX preamble.
-    # 'preamble': '',
-}
-
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).