Follow the new PTI for document build

For compliance with the Project Testing Interface as described in:
https://governance.openstack.org/tc/reference/project-testing-interface.html
http://lists.openstack.org/pipermail/openstack-dev/2017-December/125710.html

This patch also changes minor things in doc.

Change-Id: I545bab01d42bbddbfd30eb41dc386d8f7df8aea7

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.
+sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD
+openstackdocstheme>=1.18.1 # Apache-2.0
+reno>=2.5.0 # Apache-2.0

doc/source/contributor/readme.rst

@@ -1 +1,4 @@
+============
+Introduction
+============
 .. include:: ../../../README.rst

doc/source/index.rst

@@ -29,5 +29,4 @@ Indices and tables
 ------------------
 
 * :ref:`genindex`
-* :ref:`modindex`
 * :ref:`search`

test-requirements.txt

@@ -6,11 +6,8 @@ hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 
 coverage!=4.4,>=4.0 # Apache-2.0
 python-subunit>=1.0.0 # Apache-2.0/BSD
-sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD
-openstackdocstheme>=1.18.1 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
-reno>=2.5.0 # Apache-2.0
 mock>=2.0.0 # BSD

tox.ini

@@ -24,7 +24,11 @@ commands = {posargs}
 commands = python setup.py test --coverage --testr-args='{posargs}'
 
 [testenv:docs]
-commands = python setup.py build_sphinx
+deps =
+       -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+       -r{toxinidir}/requirements.txt
+       -r{toxinidir}/doc/requirements.txt
+commands = sphinx-build -b html doc/source doc/build/html
 
 [testenv:debug]
 commands = oslo_debug_helper {posargs}
@@ -38,4 +42,8 @@ builtins = _
 exclude=.venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,build
 
 [testenv:releasenotes]
+deps =
+       -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+       -r{toxinidir}/requirements.txt
+       -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html