Reconfigure tox.ini

Increase tox minversion to 3.9.0 to be compatible with inline
comments [1]

Move some test requirements to tox.ini

Remove lower-constraints environment from tox.ini

[1] https://tox.readthedocs.io/en/latest/changelog.html#v3-9-0-2019-04-17

Change-Id: Ida88627aace41c4f445a108d22e5eed12247a127

test-requirements.txt

@@ -2,16 +2,8 @@
 # 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
-doc8>=0.6.0 # Apache-2.0
 python-subunit>=1.0.0 # Apache-2.0/BSD
 oslotest>=3.2.0 # Apache-2.0
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
 os-testr>=1.0.0 # Apache-2.0
-reno>=2.5.0 # Apache-2.0
-flake8-import-order>=0.17.1 # LGPLv3
-pycodestyle>=2.0.0,<2.7.0 # MIT
-

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-minversion = 3.2.1
+minversion = 3.9.0
 skipsdist = True
 envlist = py3,pep8
 ignore_basepython_conflict=true
@@ -21,6 +21,11 @@ commands =
 passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 
 [testenv:pep8]
+deps =
+    hacking>=3.1.0,<4.0.0 # Apache-2.0
+    doc8>=0.6.0 # Apache-2.0
+    flake8-import-order>=0.17.1 # LGPLv3
+    pycodestyle>=2.0.0,<2.7.0 # MIT
 commands =
     flake8 {posargs}
     doc8 README.rst CONTRIBUTING.rst HACKING.rst doc/source
@@ -29,6 +34,9 @@ commands =
 commands = {posargs}
 
 [testenv:cover]
+deps =
+    {[testenv]deps}
+    coverage!=4.4,>=4.0 # Apache-2.0
 setenv =
     VIRTUAL_ENV={envdir}
     LANGUAGE=en_US
@@ -59,8 +67,9 @@ commands = oslo_debug_helper {posargs}
 
 [testenv:releasenotes]
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
-  -r{toxinidir}/doc/requirements.txt
+    reno>=2.5.0 # Apache-2.0
+    -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+    -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [flake8]
@@ -68,9 +77,3 @@ application-import-names = ironic_staging_drivers
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 import-order-style = pep8
 show-source = True
-
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/extra-requirements.txt