This change removes the now unused "warnerrors" setting,
which is replaced by "warning-is-error" in sphinx
releases >= 1.5[0]. This also fixes any warnings
that came up when testing with the latest version
of sphinx:
- Redundant loading of todo extension
- Empty man_pages config value
Also updated the requirements for pbr and sphinx to the latest
version(s) in requirements.txt
With this change, any doc warnings will cause the build to fail
[0] http://lists.openstack.org/pipermail/openstack-dev/2017-March/113085.html
Change-Id: Id828161e866da6766d88ce553a3c5ea2593b8f84
bhavani.cr