Fixes for tox 4.0

- passenv needed better structure
- usedevelop no longer allowed alongside skipsdist

Change-Id: I22dae3b1e4cca2dc328c21e889acf7fe98a80e0b

tox.ini

@@ -1,11 +1,9 @@
 [tox]
 minversion = 3.18.0
-skipsdist = True
 envlist = py3,functional,pep8
 ignore_basepython_conflict=true
 
 [testenv]
-usedevelop = True
 basepython = python3
 setenv =
   VIRTUAL_ENV={envdir}
@@ -19,7 +17,13 @@ deps =
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
 commands = stestr run {posargs}
-passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
+passenv =
+    http_proxy
+    HTTP_PROXY
+    https_proxy
+    HTTPS_PROXY
+    no_proxy
+    NO_PROXY
 
 [testenv:functional]
 # Define virtualenv directory, port to use for functional testing, and number
@@ -33,8 +37,7 @@ setenv =
 commands = stestr run {posargs}
 
 [testenv:pep8]
-usedevelop = False
-deps=
+deps =
     hacking>=4.1.0,<5.0.0 # Apache-2.0
     bashate>=0.5.1 # Apache-2.0
     flake8-import-order>=0.17.1 # LGPLv3
@@ -87,7 +90,6 @@ commands =
   make -C doc/build/pdf
 
 [testenv:releasenotes]
-usedevelop = False
 deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/xena}
   -r{toxinidir}/doc/requirements.txt
@@ -126,7 +128,6 @@ commands =
   oslo-config-generator --config-file=tools/config/ipa-config-generator.conf
 
 [testenv:bandit]
-usedevelop = False
 deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/xena}
   -r{toxinidir}/test-requirements.txt