pbr>=0.6,!=0.7,<1.0
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 # Apache-2.0
yasfb>=0.5.1

pbr>=0.6,!=0.7,<1.0
sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4' # BSD
openstackdocstheme>=1.20.0 # Apache-2.0
yasfb>=0.5.1

Drop python 2.7 support and testing
Drop python 2.7 support and testing

OpenStack is dropping the py2.7 support in ussuri cycle.

ironic-specs is ready with python 3 and ok to drop the
python 2.7 support.

Complete discussion & schedule can be found in
- http://lists.openstack.org/pipermail/openstack-discuss/2019-October/010142.html
- https://etherpad.openstack.org/p/drop-python2-support

Ussuri Communtiy-wide goal - https://review.opendev.org/#/c/691178/

The only reference for py27 is on requirements.

Change-Id: I40148862c8ee7a0028266b08006b877d57298ac2
