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: Ica74f2982a75e3faf7a5244390f2299381eb5b89

doc/requirements.txt

@@ -4,7 +4,7 @@
 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
 os-api-ref>=1.4.0 # Apache-2.0
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.20.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0
 sphinxcontrib-apidoc>=0.2.0  # BSD
 whereto>=0.3.0  # Apache-2.0

doc/source/conf.py

@@ -210,11 +210,6 @@ html_theme_path = [openstackdocstheme.get_html_theme_path()]
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
 
-# 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'
-
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
 #html_use_smartypants = True

lower-constraints.txt

@@ -57,7 +57,7 @@ msgpack==0.5.6
 netaddr==0.7.19
 netifaces==0.10.6
 networkx==1.11
-openstackdocstheme==1.18.1
+openstackdocstheme==1.20.0
 os-api-ref==1.4.0
 os-client-config==1.29.0
 os-testr==1.0.0