Move doc requirements to doc/requirements.txt

This is the standard way to handle doc requirements now.

Change-Id: I2487e70168566506df3c34687ca4cfa1bdd2ef4a

oslo.{{cookiecutter.module_name}}/doc/requirements.txt

@@ -0,0 +1,7 @@
+# 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,<2.0.0;python_version=='2.7' # BSD
+sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4' # BSD
+openstackdocstheme>=1.20.0

oslo.{{cookiecutter.module_name}}/test-requirements.txt

@@ -4,8 +4,3 @@
 
 hacking<0.11,>=0.10.0
 oslotest>=1.5.1
-
-# These are needed for docs generation
-sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7' # BSD
-sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4' # BSD
-openstackdocstheme>=1.20.0

oslo.{{cookiecutter.module_name}}/tox.ini

@@ -30,6 +30,7 @@ commands =
 
 [testenv:docs]
 commands = sphinx-build -W -b html doc/source doc/build/html
+deps = -r{toxinidir}/doc/requirements.txt
 
 [testenv:debug]
 commands = oslo_debug_helper {posargs}