docs: Define locale directory

Define locale directory to enable
doc translations on other languages.

F.e. https://docs.openstack.org/horizon/latest/ru/user/index.html
returns 404 error, although translation for that page was imported.

Change-Id: I282eb05ea387f0ff498da5dfe9d9650a29f3f0f9

bindep.txt

@@ -5,3 +5,5 @@ firefox-esr [selenium platform:debian]
 xvfb [selenium platform:dpkg]
 # already part of xorg-x11-server on openSUSE
 xorg-x11-server-Xvfb [selenium platform:redhat]
+# Required to build language docs
+gettext

doc/requirements.txt

@@ -1,6 +1,7 @@
-openstackdocstheme>=2.2.0 # Apache-2.0
+openstackdocstheme>=2.2.1 # Apache-2.0
 reno>=3.1.0 # Apache-2.0
 sphinx>=2.0.0 # BSD
+sphinxcontrib-svg2pdfconverter>=0.1.0 # BSD
 doc8>=0.8.1 # Apache-2.0
 
 # The below is rewquired to build testing module reference

doc/source/conf.py

@@ -110,7 +110,7 @@ copyright = '2012, OpenStack Foundation'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
-# language = None
+language = 'en'
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
@@ -342,3 +342,5 @@ epub_copyright = '2012, OpenStack'
 
 # Allow duplicate toc entries.
 # epub_tocdup = True
+
+locale_dirs = ['locale/']

tox.ini

@@ -153,6 +153,9 @@ deps =
 commands =
   sphinx-build -j auto -W -b html doc/source doc/build/html
   doc8 doc/source
+  docstheme-build-translated.sh
+setenv =
+  SPHINX_WARNINGS_TRANS=1
 
 [testenv:venv-docs]
 deps = {[testenv:docs]deps}