Move doc related modules to doc/requirements.txt

Because sphinx and oslosphinx module is not for the unit test.
I remove sphinx and oslosphinx from test-requirements.txt.
Add doc/requirements.txt and modify doc/source/_static/conf.py

Beacause of the build of py27 is failed(Zuul), I write this patch.

Change-Id: I306795ca0192675d8ffb9bbc2f1fa04165a45209

doc/requirements.txt

@@ -0,0 +1,6 @@
+# The order of packages is significant, because pip processes them in the order
+# of appearance. Changing the order has an impact on the overall integration
+# process, which may cause wedges in the gate later.
+openstackdocstheme>=1.18.1 # Apache-2.0
+reno>=2.5.0 # Apache-2.0
+sphinx>=1.6.2 # BSD

doc/source/conf.py

@@ -17,7 +17,7 @@ import os
 extensions = ['sphinx.ext.autodoc',
               'sphinx.ext.todo',
               'sphinx.ext.viewcode',
-              'oslosphinx'
+              'openstackdocstheme'
              ]
 
 todo_include_todos = True

test-requirements.txt

@@ -8,6 +8,4 @@ docutils>=0.11 # OSI-Approved Open Source, Public Domain
 stestr>=1.0.0 # Apache-2.0
 mock>=2.0 # BSD
 fixtures>=3.0.0 # Apache-2.0/BSD
-sphinx>=1.6.2 # BSD
-oslosphinx>=4.7.0 # Apache-2.0
 feedparser>=5.2.1

tox.ini

@@ -20,8 +20,13 @@ commands = {posargs}
 
 [testenv:docs]
 basepython = python3
+deps = -r{toxinidir}/requirements.txt
+       -r{toxinidir}/test-requirements.txt
+       -r{toxinidir}/doc/requirements.txt
 commands =
-   python setup.py build_sphinx {posargs}
+   rm -rf doc/build
+   sphinx-build -W -b html doc/source doc/build/html
+whitelist_externals = rm
 
 [testenv:pep8]
 basepython = python3