Drop test for lower constraints

As we agreed, drop lower constraints test from stable branches to avoid
difficulty of maintaining package depencencies for the recent pip
dependency resolver.

Signed-off-by: Yasufumi Ogawa <yasufum.o@gmail.com>
Change-Id: I5310301e09b71d4401f70ef70d71ad7c9ff9762f

.zuul.yaml

@@ -241,7 +241,6 @@
     templates:
       - check-requirements
       - openstack-cover-jobs
-      - openstack-lower-constraints-jobs
       - openstack-python3-victoria-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3

lower-constraints.txt

@@ -1,157 +0,0 @@
-alabaster==0.7.10
-alembic==0.9.6
-amqp==2.4.0
-anyjson==0.3.3
-appdirs==1.4.3
-asn1crypto==0.24.0
-bcrypt==3.1.4
-beautifulsoup4==4.6.0
-cachetools==2.0.1
-castellan==0.16.0
-certifi==2018.1.18
-cffi==1.14.0
-chardet==3.0.4
-cliff==2.11.0
-cmd2==0.8.2
-contextlib2==0.5.5
-coverage==4.0
-cryptography==2.7
-ddt===1.0.1
-debtcollector==1.19.0
-decorator==4.4.1
-deprecation==2.0
-doc8==0.6.0
-docutils==0.14
-dogpile.cache==0.6.5
-dulwich==0.19.0
-enum-compat==0.0.2
-eventlet==0.18.2
-extras==1.0.0
-fasteners==0.14.1
-fixtures==3.0.0
-future==0.16.0
-futurist==2.1.0
-glance-store==2.3.0
-google-auth==1.4.1
-greenlet==0.4.15
-heat-translator==2.0.0
-idna==2.6
-imagesize==1.0.0
-ipaddress==1.0.19
-iso8601==0.1.12
-Jinja2==2.10
-jmespath==0.9.3
-jsonpatch==1.21
-jsonpointer==2.0
-jsonschema==3.2.0
-keystoneauth1==3.18.0
-keystonemiddleware==4.17.0
-kombu==4.3.0
-kubernetes==11.0.0
-linecache2==1.0.0
-Mako==1.0.7
-MarkupSafe==1.1
-monotonic==1.4
-mox3==0.25.0
-msgpack==0.5.6
-munch==2.2.0
-netaddr==0.7.18
-netifaces==0.10.6
-oauthlib==2.0.7
-openstacksdk==0.44.0
-os-api-ref==1.5.0
-os-client-config==1.29.0
-os-service-types==1.7.0
-osc-lib==1.10.0
-oslo.cache==1.29.0
-oslo.concurrency==3.26.0
-oslo.config==5.2.0
-oslo.context==2.19.2
-oslo.db==5.0.0
-oslo.i18n==3.20.0
-oslo.log==3.36.0
-oslo.messaging==9.3.0
-oslo.middleware==3.31.0
-oslo.policy==1.30.0
-oslo.reports==1.18.0
-oslo.rootwrap==5.8.0
-oslo.serialization==2.18.0
-oslo.service==1.24.0
-oslo.upgradecheck==0.1.0
-oslo.utils==3.33.0
-oslo.versionedobjects==1.33.3
-oslotest==3.2.0
-packaging==17.1
-paramiko==2.0.0
-Paste==2.0.2
-PasteDeploy==1.5.0
-pbr==2.0.0
-pkg-resources==0.0.0
-prettytable==0.7.2
-psutil==5.4.3
-pyasn1-modules==0.2.1
-pyasn1==0.4.2
-pycadf==2.7.0
-pycparser==2.18
-Pygments==2.2.0
-pyinotify==0.9.6
-PyNaCl==1.2.1
-pyOpenSSL==17.5.0
-pyparsing==2.2.0
-pyperclip==1.6.0
-pyroute2==0.4.21
-python-barbicanclient==4.5.2
-python-blazarclient==1.0.1
-python-dateutil==2.7.2
-python-editor==1.0.3
-python-glanceclient==2.9.1
-python-heatclient==1.10.0
-python-keystoneclient==3.8.0
-python-mimeparse==1.6.0
-python-mistralclient==3.1.0
-python-neutronclient==6.7.0
-python-novaclient==9.1.0
-python-subunit==1.0.0
-python-swiftclient==3.5.0
-python-tackerclient==0.8.0
-pytz==2018.3
-PyYAML==5.1
-repoze.lru==0.7
-requests-oauthlib==0.8.0
-requests==2.20.0
-requests-mock==1.2.0
-requestsexceptions==1.4.0
-restructuredtext-lint==1.1.3
-rfc3986==1.1.0
-Routes==2.3.1
-rsa==3.4.2
-setuptools==21.0.0
-simplejson==3.13.2
-six==1.11.0
-snowballstemmer==1.2.1
-sqlalchemy-filters==0.10.0
-sqlalchemy-migrate==0.11.0
-SQLAlchemy==1.3.0
-sqlparse==0.2.4
-statsd==3.2.2
-stestr==2.0.0
-stevedore==1.20.0
-tempest==22.0.0
-Tempita==0.5.2
-tenacity==4.12.0
-testresources==2.0.1
-testscenarios==0.5.0
-testtools==2.2.0
-tooz==1.58.0
-tosca-parser==1.6.1
-traceback2==1.4.0
-unittest2==1.1.0
-urllib3==1.24.2
-vine==1.1.4
-voluptuous==0.11.1
-waitress==1.1.0
-warlock==1.3.3
-WebOb==1.7.1
-websocket-client==0.47.0
-WebTest==2.0.27
-wrapt==1.10.11

tox.ini

@@ -126,12 +126,6 @@ commands =
 commands =
   oslopolicy-sample-generator --config-file=etc/tacker-policy-generator.conf
 
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt
-
 [testenv:bindep]
 # Do not install any requirements. We want this to be fast and work even if
 # system dependencies are missing, since it's used to tell you what system