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: Iacccbabe71f3b68bdf28ecc349571887f191a3cd

doc/requirements.txt

@@ -1,4 +1,4 @@
 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,!=2.1.0,>=1.6.2;python_version>='3.4'  # BSD
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.20.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0

doc/source/conf.py

@@ -26,7 +26,6 @@ extensions = [
 repository_name = 'openstack/os-vif'
 bug_project = 'os-vif'
 bug_tag = ''
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
 
 # The suffix of source filenames.
 source_suffix = '.rst'
@@ -35,7 +34,6 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'os-vif'
 copyright = u'2016, OpenStack Foundation'
 
 # If true, '()' will be appended to :func: etc. cross-reference text.

lower-constraints.txt

@@ -34,7 +34,7 @@ msgpack-python==0.4.0
 msgpack==0.5.6
 netaddr==0.7.18
 netifaces==0.10.6
-openstackdocstheme==1.17.0
+openstackdocstheme==1.20.0
 os-client-config==1.28.0
 oslo.concurrency==3.20.0
 oslo.config==5.1.0

releasenotes/source/conf.py

@@ -30,7 +30,6 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'os-vif release Notes'
 copyright = u'2017, OpenStack Foundation'
 
 # Release notes do not need a version in the title, they span