Remove lower-constraints remnants

Change-Id: I21c0ca526394796fb60d50cc5e2a703c575b68bd

lower-constraints.txt

-alabaster==0.7.10
-Babel==2.3.4
-bandit==1.6.0
-coverage==4.0
-ddt==1.0.1
-debtcollector==1.2.0
-docutils==0.11
-dulwich==0.15.0
-eventlet==0.18.2
-extras==1.0.0
-fasteners==0.7.0
-fixtures==3.0.0
-gitdb==0.6.4
-GitPython==1.0.1
-greenlet==0.4.15
-imagesize==0.7.1
-iso8601==0.1.11
-Jinja2==2.10
-linecache2==1.0.0
-lxml==4.5.0
-MarkupSafe==1.0
-netaddr==0.7.18
-netifaces==0.10.4
-oslo.concurrency==3.26.0
-oslo.config==5.2.0
-oslo.context==2.19.2
-oslo.i18n==3.15.3
-oslo.utils==3.33.0
-pbr==2.0.0
-Pygments==2.2.0
-pyparsing==2.1.0
-python-mimeparse==1.6.0
-python-subunit==1.0.0
-pytz==2013.6
-PyYAML==3.13
-requests==2.14.2
-rfc3986==0.3.1
-smmap==0.9.0
-snowballstemmer==1.2.1
-stestr==2.0.0
-stevedore==1.20.0
-suds-jurko==0.6
-testtools==2.2.0
-traceback2==1.4.0
-unittest2==1.1.0
-urllib3==1.21.1
-wrapt==1.7.0

tox.ini

@@ -76,9 +76,3 @@ commands =
 # explicitly to avoid unnecessarily installing the checked-out repo too.
 deps = bindep
 commands = bindep test
-
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt