Remove lower-constraints remnants

These were missed in change: I36fb12c92823d27e42975d4dc683ad8d99191a77

Change-Id: Ic757469ae8c9af7b0f83f94e2d902f33385f60ef

lower-constraints.txt

@@ -1,48 +0,0 @@
-alabaster==0.7.10
-Babel==2.3.4
-chardet==3.0.4
-cliff==3.2.0
-cmd2==0.8.9
-coverage==4.0
-doc8==0.8.1
-docutils==0.11
-dulwich==0.15.0
-entrypoints==0.3
-extras==1.0.0
-fixtures==3.0.0
-future==0.18.2
-imagesize==0.7.1
-Jinja2==2.10
-linecache2==1.0.0
-MarkupSafe==1.0
-openstackdocstheme==2.2.1
-packaging==20.4
-pbr==2.0.0
-prettytable==0.7.2
-Pygments==2.2.0
-pyparsing==2.4.7
-pyperclip==1.8.0
-python-mimeparse==1.6.0
-python-subunit==1.0.0
-pytz==2013.6
-PyYAML==3.12
-reno==3.1.0
-requests==2.14.2
-restructuredtext-lint==1.1.1
-six==1.10.0
-snowballstemmer==1.2.1
-Sphinx==2.0.0
-sphinxcontrib-applehelp==1.0.2
-sphinxcontrib-devhelp==1.0.2
-sphinxcontrib-htmlhelp==1.0.3
-sphinxcontrib-jsmath==1.0.1
-sphinxcontrib-qthelp==1.0.3
-sphinxcontrib-serializinghtml==1.1.4
-stestr==2.0.0
-stevedore==1.20.0
-testtools==2.2.0
-traceback2==1.4.0
-unittest2==1.1.0
-voluptuous==0.11.7
-wcwidth==0.2.4
-wrapt==1.7.0

tox.ini

@@ -47,8 +47,3 @@ exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 [testenv:releasenotes]
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt