Remove lower-constraints remnants

These were missed in change: Ic086f5e9a7a8b9c9050ef27993f339d52ad1e236

Change-Id: Ifbfb33e18c95a3bf01dd522835d1246989e78242

lower-constraints.txt

@@ -1,51 +0,0 @@
-appdirs==1.3.0
-Babel==2.3.4
-cliff==3.1.0
-cmd2==0.8.9
-coverage==4.0
-debtcollector==1.2.0
-dnspython==1.16.0
-entrypoints==0.3
-eventlet==0.19.0
-extras==1.0.0
-fasteners==0.7.0
-fixtures==3.0.0
-future==0.18.2
-gitdb==0.6.4
-GitPython==1.0.1
-greenlet==0.4.13
-iso8601==0.1.11
-keystoneauth1==3.4.0
-linecache2==1.0.0
-mock==4.0.2
-monotonic==1.5
-mox3==0.20.0
-netaddr==0.7.18
-netifaces==0.10.4
-os-client-config==1.28.0
-oslo.config==5.2.0
-oslo.i18n==3.15.3
-oslo.utils==3.33.0
-oslotest==3.2.0
-pbr==2.0.0
-prettytable==0.7.2
-pyparsing==2.1.0
-pyperclip==1.8.0
-python-mimeparse==1.6.0
-python-subunit==1.0.0
-pytz==2013.6
-PyYAML==3.12
-requests==2.14.2
-requestsexceptions==1.2.0
-rfc3986==0.3.1
-six==1.10.0
-smmap==0.9.0
-stestr==2.0.0
-stevedore==1.20.0
-testrepository==0.0.20
-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

@@ -56,8 +56,3 @@ deps = {[testenv:docs]deps}
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees --keep-going -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