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.

Correct the wrong theme

Change-Id: I669171297a48e55430e8ce3110c4a30c20351678

doc/requirements.txt

@@ -1,7 +1,7 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.20.0 # 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
 reno>=2.5.0 # Apache-2.0

doc/source/conf.py

@@ -29,7 +29,6 @@ extensions = [
 repository_name = 'openstack/python-zunclient'
 bug_project = 'python-zunclient'
 bug_tag = 'doc'
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
 
 # autodoc generation is a bit aggressive and a nuisance when doing heavy
 # text edit cycles.
@@ -42,7 +41,6 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'python-zunclient'
 copyright = u'2013, OpenStack Foundation'
 
 # If true, '()' will be appended to :func: etc. cross-reference text.