Fix lower-constraints with the new pip resolver

* Move pep8 deps from test-requirements.txt to tox.ini. They are not
needed in test-requirements.txt and difficult to constrain there.
* Bump MarkupSafe to get rid of
`cannot import name 'Feature' from 'setuptools'`

Change-Id: I27522a0e2d208922ad1c2313c0ad9ca1407fac7b

lower-constraints.txt

@@ -14,7 +14,7 @@ iso8601==0.1.11
 Jinja2==2.10
 keystoneauth1==3.4.0
 linecache2==1.0.0
-MarkupSafe==1.0
+MarkupSafe==1.1.1
 mccabe==0.2.1
 mox3==0.20.0
 openstackdocstheme==1.18.1

test-requirements.txt

@@ -2,8 +2,6 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking>=3.1.0,<4.0.0 # Apache-2.0
-
 coverage!=4.4,>=4.0 # Apache-2.0
 python-subunit>=1.0.0 # Apache-2.0/BSD
 sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD
@@ -12,8 +10,6 @@ oslotest>=3.2.0 # Apache-2.0
 stestr>=2.0.0 # Apache-2.0
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
-flake8-import-order>=0.17.1 # LGPLv3
-pycodestyle>=2.0.0,<2.7.0 # MIT
 
 # releasenotes
 reno>=2.5.0 # Apache-2.0

tox.ini

@@ -18,6 +18,10 @@ deps =
 commands = stestr run --slowest {posargs}
 
 [testenv:pep8]
+deps =
+  hacking>=3.1.0,<4.0.0 # Apache-2.0
+  flake8-import-order>=0.17.1 # LGPLv3
+  pycodestyle>=2.0.0,<2.7.0 # MIT
 commands = flake8 {posargs}
 
 [testenv:venv]