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: I281cd6451968c76cb55d9213aeb5a8da35e006a0
Depends-On: https://review.openstack.org/555034
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

.zuul.yaml

@@ -0,0 +1,7 @@
+- project:
+    check:
+      jobs:
+        - openstack-tox-lower-constraints
+    gate:
+      jobs:
+        - openstack-tox-lower-constraints

lower-constraints.txt

@@ -0,0 +1,66 @@
+appdirs==1.4.3
+Babel==2.5.3
+bandit==1.4.0
+certifi==2018.1.18
+cffi==1.11.5
+chardet==3.0.4
+click==6.7
+daiquiri==1.3.0
+debtcollector==1.19.0
+dogpile.cache==0.6.5
+extras==1.0.0
+fixtures==3.0.0
+flake8==2.5.5
+gitdb2==2.0.3
+GitPython==2.1.8
+hacking==0.12.0
+idna==2.6
+iso8601==0.1.12
+Jinja2==2.10
+keystoneauth1==3.4.0
+linecache2==1.0.0
+MarkupSafe==1.0
+mccabe==0.2.1
+mock==2.0.0
+monotonic==1.4
+mox3==0.25.0
+msgpack==0.5.6
+netaddr==0.7.19
+netifaces==0.10.6
+openstack-requirements==1.2.0
+os-client-config==1.29.0
+oslo.config==5.2.0
+oslo.context==2.20.0
+oslo.i18n==3.20.0
+oslo.log==3.37.0
+oslo.serialization==2.25.0
+oslo.utils==3.36.0
+oslotest==3.3.0
+packaging==17.1
+Parsley==1.3
+pbr==3.1.1
+pep8==1.5.7
+pifpaf==2.0.7
+psutil==5.4.3
+pycparser==2.18
+pyflakes==0.8.1
+pyinotify==0.9.6
+pyparsing==2.2.0
+python-dateutil==2.7.0
+python-mimeparse==1.6.0
+python-subunit==1.2.0
+pytz==2018.3
+PyYAML==3.12
+requests==2.18.4
+requestsexceptions==1.4.0
+rfc3986==1.1.0
+six==1.11.0
+smmap2==2.0.3
+stevedore==1.28.0
+testrepository==0.0.20
+testtools==2.3.0
+traceback2==1.4.0
+unittest2==1.1.0
+urllib3==1.22
+wrapt==1.10.11
+xattr==0.9.3

tox.ini

@@ -64,3 +64,10 @@ commands = pip-missing-reqs -d --ignore-module=oslo_cache* --ignore-file=oslo_ca
 [testenv:releasenotes]
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
+
+[testenv:lower-constraints]
+basepython = python3
+deps =
+  -c{toxinidir}/lower-constraints.txt
+  -r{toxinidir}/test-requirements.txt
+  .[dogpile,mongo,etcd3gw]