Cleanup tox.ini.

tox.ini

 [tox]
-envlist = py26,py27,pypy,py32,py33,py34
+envlist = py26, py27, py33, py34, pypy, pypy3
 skipsdist = True
 
 [testenv]
+usedevelop = True
 commands =
- pip install --allow-all-external -e .
- nosetests
- flake8 astor tests
+ - nosetests
+ - flake8 astor tests
 deps =
  -rrequirements-dev.txt
-
-[testenv:py26]
-deps =
- {[testenv]deps}
- unittest2
+ py26: unittest2