Update docs building

Switch to using sphinx-build, update requirements of openstackdocstheme
and Sphinx for python 3.

Remove Babel, it's not needed anymore See
http://lists.openstack.org/pipermail/openstack-discuss/2020-April/014227.html.

Change-Id: I14ca880507873e952c1f887dac7f3f2973a036cb

babel.cfg

@@ -1,2 +0,0 @@
-[python: **.py]
-

requirements.txt

@@ -3,7 +3,6 @@
 # process, which may cause wedges in the gate later.
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 
-Babel!=2.4.0,>=2.3.4 # BSD
 six>=1.10.0 # MIT
 keystoneauth1>=3.3.0 # Apache-2.0
 stevedore>=1.20.0 # Apache-2.0

setup.cfg

@@ -62,5 +62,4 @@ input_file = cyborgclient/locale/cyborgclient.pot
 
 [extract_messages]
 keywords = _ gettext ngettext l_ lazy_gettext
-mapping_file = babel.cfg
 output_file = cyborgclient/locale/cyborgclient.pot

test-requirements.txt

@@ -6,11 +6,11 @@ hacking>=3.0,<3.1.0 # Apache-2.0
 
 coverage>=4.0,!=4.4 # Apache-2.0
 python-subunit>=0.0.18 # Apache-2.0/BSD
-sphinx>=1.8.0,!=2.1.0 # BSD
+sphinx>=2.0.0,!=2.1.0 # BSD
 oslotest>=1.10.0 # Apache-2.0
 stestr>=1.0.0 # Apache-2.0
 testtools>=1.4.0 # MIT
-openstackdocstheme>=1.20.0  # Apache-2.0
+openstackdocstheme>=2.0.0  # Apache-2.0
 requests-mock>=0.6.0  # Apache-2.0
 # releasenotes
-reno>=1.8.0 # Apache-2.0
+reno>=2.5.0 # Apache-2.0

tox.ini

@@ -36,7 +36,7 @@ commands =
     coverage xml -o cover/coverage.xml
 
 [testenv:docs]
-commands = python setup.py build_sphinx
+commands = sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:releasenotes]
 commands =