Fix "not in openstack/requirements" of Pygments package

[Nguyen Van Trung]

This bug will raise D000 when use doc8 for further check in pep8 of each project.

Currenttly, Openstack Designate must ignore D000 for check along with pep8 & doc8 [1]. We also hit error when use tox -epep8 without Pygments package, as below:

/home/stack/CODE_REVIEW/designate/doc/source/admin/backends/bind9.rst:41: D000 Cannot analyze code. Pygments package not found.
/home/stack/CODE_REVIEW/designate/doc/source/admin/backends/bind9.rst:54: D000 Cannot analyze code. Pygments package not found.
/home/stack/CODE_REVIEW/designate/doc/source/admin/backends/bind9.rst:60: D000 Cannot analyze code. Pygments package not found.
/home/stack/CODE_REVIEW/designate/doc/source/admin/backends/knot2_agent.rst:46: D000 Cannot analyze code. Pygments package not found.
/home/stack/CODE_REVIEW/designate/doc/source/admin/backends/knot2_agent.rst:59: D000 Cannot analyze code. Pygments package not found.
/home/stack/CODE_REVIEW/designate/doc/source/admin/backends/knot2_agent.rst:127: D000 Cannot analyze code. Pygments package not found.
/home/stack/CODE_REVIEW/designate/doc/source/admin/backends/knot2_agent.rst:145: D000 Cannot analyze code. Pygments package not found.
/home/stack/CODE_REVIEW/designate/doc/source/admin/backends/knot2_agent.rst:154: D000 Cannot analyze code. Pygments package not found.
/home/stack/CODE_REVIEW/designate/doc/source/admin/backends/knot2_agent.rst:179: D000 Cannot analyze code. Pygments package not found.

Beside, I also has pushed commit which remove ignore D000 [2] but I got message
"Requirement set([Requirement(package=u'Pygments', location='',
 specifiers='>=2.2.0', markers=u'', comment='', extras=frozenset([]))])
 not in openstack/requirements".

[1] https://github.com/openstack/designate/blob/master/tox.ini#L74
[2] https://review.openstack.org/#/c/567458/

[Matthew Thode (prometheanfire)]

I need more details, how can I reproduce this error.

[Matthew Thode (prometheanfire)]

If we don't get a response soon I'm going to close this.

[Nguyen Van Trung (trungnv)]

Sorry Matthew, I had fixed it in https://review.openstack.org/#/c/568729/. I don't know why this fixing cannot link into this bug. Thanks