Build pdf docs

This follows the instructions [1] in an attempt to build pdf docs.

This creates workable results, but there is room for improvement.

[1] https://etherpad.openstack.org/p/train-pdf-support-goal

Change-Id: Icf7c22bf9d1de6fb2a74a756c370930d4c00b0b9
Story: 2006110
Task: 35395

doc/source/conf.py

@@ -73,7 +73,7 @@ htmlhelp_basename = '%sdoc' % project
 # [howto/manual]).
 latex_documents = [
     ('index',
-     '%s.tex' % project,
+     'doc-%s.tex' % project,
      u'%s Documentation' % project,
      u'OpenStack Developers', 'manual'),
 ]

tox.ini

@@ -44,6 +44,15 @@ deps =
   -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -W -b html doc/source doc/build/html
 
+[testenv:pdf-docs]
+basepython = python3
+deps = {[testenv:docs]deps}
+whitelist_externals =
+  make
+commands =
+  sphinx-build -W -b latex doc/source doc/build/pdf
+  make -C doc/build/pdf
+
 [testenv:releasenotes]
 deps = {[testenv:docs]deps}
 commands =