Create a tox environment for running the unit tests against the lower
bounds of the dependencies.
Create a lower-constraints.txt to be used to enforce the lower bounds
in those tests.
Add openstack-tox-lower-constraints job to the zuul configuration.
See http://lists.openstack.org/pipermail/openstack-dev/2018-March/128352.html
for more details.
Also fix the lower bound for requests-kerberos.
Change-Id: Ie5da1d132321b2cffea3eb8522462daad45900b5
Depends-On: https://review.openstack.org/555034
Signed-off-by: Doug Hellmann <doug@doughellmann.com>
keystoneauth depends on some libraries being installed for tests to
work. Broadly we track those in bindep.txt files. Add one.
Change-Id: Ie8e86ce50e337dcc65159d54d967427e10463c61