OSPurge; rework tox.ini to test multiple versions of Python

Change-Id: I01e0b61c1a39c9ce8fe425ac4c0922fc8c18ce4e

test-requirements.txt

@@ -2,7 +2,6 @@ bashate>=0.2 # Apache-2.0
 coverage>=4.0  # Apache-2.0
 doc8  # Apache-2.0
 hacking>=0.12.0,<0.13  # Apache-2.0
-mypy-lang
 openstackdocstheme>=1.5.0  # Apache-2.0
 sphinx>=1.2.1,!=1.3b1,<1.4  # BSD
 testrepository>=0.0.18  # Apache-2.0/BSD

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = pep8,pip-check-reqs,coverage
+envlist = pep8,pip-check-reqs,cover,py35
 minversion = 1.9
 skipsdist = True
 
@@ -7,10 +7,15 @@ skipsdist = True
 deps =
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/test-requirements.txt
-basepython = python3.5
+basepython =
+    run,pep8,cover,mypy,pip-check-reqs,py35: python3.5
+    docs,venv: python2
 commands =
     python setup.py testr --testr-args='{posargs}'
 
+[testenv:venv]
+commands = {posargs}
+
 [testenv:run]
 usedevelop=True
 deps =
@@ -28,16 +33,17 @@ commands =
     bash -c "find {toxinidir}/tools -type f -name *.sh \
          -print0 | xargs -0 bashate -v -iE006 -eE005,E042"
 
-[testenv:coverage]
+[testenv:cover]
 commands =
     coverage erase
-    coverage run --source=ospurge -m unittest discover --verbose
-    coverage report --omit="ospurge/tests/*" --show-missing --skip-covered --fail-under 100
+    python setup.py testr --coverage --omit="ospurge/tests/*" --testr-args='{posargs}'
+    coverage report --omit="ospurge/tests/*" --show-missing --fail-under 100
 
 [testenv:mypy]
 skip_install = True
 deps =
     -r{toxinidir}/test-requirements.txt
+    mypy-lang;python_version>'3.2'
 commands =
     mypy --check-untyped-defs --disallow-untyped-defs --silent-imports ospurge
 
@@ -59,7 +65,7 @@ deps =
     -r{toxinidir}/test-requirements.txt
 commands =
   doc8 -e .rst doc/source README.rst
-  python setup.py build_sphinx -E -b html
+  python setup.py build_sphinx -E
   echo "Documentation location: {toxinidir}/doc/build/html/index.html"
 
 [flake8]