add more tests env

tox.ini

 [tox]
-envlist = py25,py26,py27,pypy,docs
-downloadcache = .tox/_download/
+envlist = 
+    py25-1.2.X, py26-1.2.X, py27-1.2.X,
+    py25-1.3.X, py26-1.3.X, py27-1.3.X,
+    py25, py26, py27, pypy, docs
 
 [testenv]
+downloadcache = {toxworkdir}/_download/
 setenv =
+    DJANGO_SETTINGS_MODULE = tests.settings
     PYTHONPATH = {toxinidir}
 commands =
-    {envbindir}/django-admin.py test {posargs:tests} --settings=tests.settings
+    {envbindir}/django-admin.py test {posargs:tests}
+
+[testenv:py25-1.2.X]
+basepython = python2.5
+deps =
+    Django==1.2.4
+    mock
+    django-staticfiles
+    unittest2
+
+[testenv:py26-1.2.X]
+basepython = python2.6
+deps =
+    Django==1.2.4
+    mock
+    django-staticfiles
+    unittest2
+
+[testenv:py27-1.2.X]
+basepython = python2.7
+deps =
+    Django==1.2.4
+    mock
+    django-staticfiles
+    unittest2
+
+[testenv:py25-1.3.X]
+basepython = python2.5
 deps =
     Django==1.3.1
-    mock>=0.7.2
-    django-staticfiles==1.1.2
-    unittest2==0.5.1
+    mock
+    django-staticfiles
+    unittest2
+
+[testenv:py26-1.3.X]
+basepython = python2.6
+deps =
+    Django==1.3.1
+    mock
+    django-staticfiles
+    unittest2
+
+[testenv:py27-1.3.X]
+basepython = python2.7
+deps =
+    Django==1.3.1
+    mock
+    django-staticfiles
+    unittest2
+
+[testenv:py25]
+basepython = python2.5
+deps =
+    https://github.com/django/django/zipball/master
+    mock
+    django-staticfiles
+    unittest2
+
+[testenv:py26]
+basepython = python2.6
+deps =
+    https://github.com/django/django/zipball/master
+    mock
+    django-staticfiles
+    unittest2
+
+[testenv:py27]
+basepython = python2.7
+deps =
+    https://github.com/django/django/zipball/master
+    mock
+    django-staticfiles
+    unittest2
+
+[testenv:pypy]
+basepython = pypy
+deps =
+    https://github.com/django/django/zipball/master
+    mock
+    django-staticfiles
+    unittest2
 
 [testenv:docs]
-basepython=python
+basepython = python2.7
 changedir = docs
 deps = sphinx
 commands =