Deprecate oslosphinx with openstackdocstheme

Oslosphinxs is bosolete and will be EOL after pike, this replace it with
openstackdocstheme with is the official replacement.

Also upgrade sphinx to make it compatible with newer version of yasfb.

Unit test are run with python3 so we can upgrade sphinx to >= 2.0.0

Closes-Bug: #1824074

Change-Id: Ifb28b4e656b60dc1b2dcb6da08b0e717439586ee

.zuul.yaml

@@ -3,7 +3,7 @@
       - openstack-specs-jobs
     check:
       jobs:
-        - openstack-tox-py27
+        - openstack-tox-py36
     gate:
       jobs:
-        - openstack-tox-py27
+        - openstack-tox-py36

doc/source/conf.py

@@ -24,7 +24,7 @@ sys.path.insert(0, os.path.abspath('../..'))
 extensions = [
     'sphinx.ext.autodoc',
     #'sphinx.ext.intersphinx',
-    'oslosphinx',
+    'openstackdocstheme',
     'yasfb',
 ]
 
@@ -69,6 +69,8 @@ pygments_style = 'sphinx'
 # html_theme = '_theme'
 # html_static_path = ['static']
 
+html_theme = 'openstackdocs'
+
 # Output file base name for HTML help builder.
 htmlhelp_basename = '%sdoc' % project
 

requirements.txt

@@ -1,6 +1,5 @@
-oslosphinx
+openstackdocstheme
-pbr>=0.6,<1.0
+sphinx>=2.0.0
-sphinx>=1.1.2,<1.2
 stestr>=2.0.0 # Apache-2.0
 testtools>=0.9.34
-yasfb>=0.5.1
+yasfb>=0.8.0

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 1.6
-envlist = docs,py27
+envlist = docs,py36
 skipsdist = True
 
 [testenv]