Update docs building

Update docs building:
* Switch to sphinx-build
* Update requirements for Sphinx and openstackdocstheme for
  python 3
* Remove unneeded doc and translation sections from setup.cfg

Change-Id: Ic1a93606cb73778fc43e58b85ad65bee46c3c631

setup.cfg

@@ -14,36 +14,14 @@ classifier =
     Operating System :: POSIX :: Linux
     Programming Language :: Python
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.3
     Programming Language :: Python :: 3.5
+    Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
 
 [files]
 packages =
     manila_tempest_tests
 
-[build_sphinx]
-all-files = 1
-warning-is-error = 1
-source-dir = doc/source
-build-dir = doc/build
-
-[upload_sphinx]
-upload-dir = doc/build/html
-
-[compile_catalog]
-directory = manila_tempest_tests/locale
-domain = manila_tempest_tests
-
-[update_catalog]
-domain = manila_tempest_tests
-output_dir = manila_tempest_tests/locale
-input_file = manila_tempest_tests/locale/manila-tempest-plugin.pot
-
-[extract_messages]
-keywords = _ gettext ngettext l_ lazy_gettext
-mapping_file = babel.cfg
-output_file = manila_tempest_tests/locale/manila-tempest-plugin.pot
-
 [entry_points]
 tempest.test_plugins =
     manila_tests = manila_tempest_tests.plugin:ManilaTempestPlugin

test-requirements.txt

@@ -10,6 +10,6 @@ sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD
 oslotest>=3.2.0 # Apache-2.0
 stestr>=1.0.0 # Apache-2.0
 testtools>=2.2.0 # MIT
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.31.2 # Apache-2.0
 # releasenotes
 reno>=2.5.0 # Apache-2.0

tox.ini

@@ -24,7 +24,7 @@ commands = flake8 {posargs}
 commands = {posargs}
 
 [testenv:docs]
-commands = python setup.py build_sphinx
+commands = sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:releasenotes]
 commands =