Remove lower-constraints job

This patch removes the lower-constraints job entirely. This change
is needed due to an update in the pip-dependency-resolver which
broke the lower-constraints job.

Change-Id: Ie97fec3d6edf93a1506a38ead8a17534e6bb0ccd

lower-constraints.txt

@@ -1,27 +0,0 @@
-alabaster==0.7.10
-Babel==2.5.3
-bashate==0.5.1
-certifi==2018.1.18
-chardet==3.0.4
-decorator==4.2.1
-diskimage-builder==1.1.2
-docutils==0.11
-dulwich==0.19.0
-idna==2.6
-imagesize==1.0.0
-Jinja2==2.10
-MarkupSafe==1.0
-mccabe==0.2.1
-networkx==1.11
-openstackdocstheme==2.2.1
-pbr==2.0.0
-Pygments==2.2.0
-pytz==2018.3
-PyYAML==3.12
-requests==2.18.4
-six==1.11.0
-snowballstemmer==1.2.1
-Sphinx==2.0.0
-sphinxcontrib-websupport==1.0.1
-stevedore==1.28.0
-urllib3==1.22

tox.ini

@@ -43,9 +43,3 @@ passenv = *
 show-source = true
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,tools
-
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt

zuul.d/project.yaml

@@ -2,7 +2,6 @@
     templates:
       - check-requirements
       - build-openstack-docs-pti
-      - openstack-lower-constraints-jobs
     check:
       jobs:
         - openstack-tox-pep8