add lower-constraints job

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: I6a7a78800caf3c536603ae0bcfeb03830c8a5860
Depends-On: https://review.openstack.org/555034
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/.zuul.yaml b/.zuul.yaml
index 2a784b9..14b1414 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -42,6 +42,8 @@
         - glanceclient-dsvm-functional
         - glanceclient-dsvm-functional-identity-v3-only:
             voting: false
+        - openstack-tox-lower-constraints
     gate:
       jobs:
         - glanceclient-dsvm-functional
+        - openstack-tox-lower-constraints