Move doc requirements to doc

and update tox to later version

Change-Id: I4c07e622f2285513c86f168c15b375e62b5594ad

doc/requirements.txt

@@ -2,9 +2,8 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking>=3.0.1,<3.1.0 # Apache-2.0
-
 sphinx>=2.0.0,!=2.1.0 # BSD
 openstackdocstheme>=2.2.1 # Apache-2.0
 # releasenotes
 reno>=3.1.0 # Apache-2.0
+

requirements.txt

@@ -3,8 +3,8 @@
 # process, which may cause wedges in the gate later.
 
 pbr>=2.0 # Apache-2.0
-oslo.config>=5.1.0 # Apache-2.0
+oslo.config>=6.0.0 # Apache-2.0
-oslo.utils>=3.31.0 # Apache-2.0
+oslo.utils>=3.37.0 # Apache-2.0
 six>=1.10.0 # MIT
 tempest>=17.1.0 # Apache-2.0
 gabbi>=1.30.0 # Apache-2.0

setup.cfg

@@ -19,6 +19,8 @@ classifier =
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.8
+
 
 [files]
 packages =

tox.ini

@@ -1,31 +1,38 @@
 [tox]
-minversion = 3.1.1
+minversion = 3.18.0
 envlist = py3,pypy,pep8
-skipsdist = True
 ignore_basepython_conflict = True
 
 [testenv]
 basepython = python3
+sitepackages = False
 usedevelop = True
-install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master} {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
    PYTHONWARNINGS=default::DeprecationWarning
    OS_STDOUT_CAPTURE=1
    OS_STDERR_CAPTURE=1
    OS_TEST_TIMEOUT=60
-deps = -r{toxinidir}/test-requirements.txt
+deps =
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/requirements.txt
+
 commands = stestr run {posargs}
 
 [testenv:pep8]
+deps = hacking>=3.0,<3.1.0
 commands = flake8 {posargs}
 
 [testenv:venv]
 commands = {posargs}
 
 [testenv:docs]
+deps =
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -a -E -W -b html doc/source doc/build/html
+setenv = PYTHONHASHSEED=0
 
 [testenv:releasenotes]
 commands =