Since ceilometer is introduced in upper-constraints.txt [1], tests are
failing, as ceilometer was installed via tox.ini directly from github,
but pip doesn't like that:
"Could not satisfy constraints for 'ceilometer': installation from path
or url cannot be constrained to a version"
[1] https://review.openstack.org/#/c/601498
Change-Id: I9a018f625e6f252fe64ee2b8b93f5f2e0b464309
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.
Change-Id: Ic189fc2d55534557029fec4150f7a7f3c9562d6e
Depends-On: https://review.openstack.org/555034
Signed-off-by: Doug Hellmann <doug@doughellmann.com>