Clean up tox.ini

* Don't repeat dependencies
* Reuse 'venv' for genconfig

Change-Id: I3cb011bbbacbe4708cb7e0021d7bf08c0362405e

tox.ini

@@ -18,30 +18,17 @@ commands = {posargs}
 
 [testenv:pep8]
 basepython = python2.7
-deps =
-    -r{toxinidir}/requirements.txt
-    -r{toxinidir}/test-requirements.txt
-    -r{toxinidir}/plugin-requirements.txt
 commands =
     flake8 ironic_inspector
     doc8 README.rst CONTRIBUTING.rst HTTP-API.rst
 
-[flake8]
-max-complexity=15
-
-[hacking]
-import_exceptions = ironicclient.exceptions,ironic_inspector.common.i18n
-
 [testenv:func]
 basepython = python2.7
-deps =
-    -r{toxinidir}/requirements.txt
-    -r{toxinidir}/test-requirements.txt
-    -r{toxinidir}/plugin-requirements.txt
 commands =
     python -m ironic_inspector.test.functional
 
 [testenv:genconfig]
+envdir = {toxworkdir}/venv
 commands =
     oslo-config-generator \
     --output-file example.conf \
@@ -49,3 +36,9 @@ commands =
     --namespace keystonemiddleware.auth_token \
     --namespace ironic_inspector.common.swift \
     --namespace oslo.db
+
+[flake8]
+max-complexity=15
+
+[hacking]
+import_exceptions = ironicclient.exceptions,ironic_inspector.common.i18n