Implemented TokenDef ordering similar to Django Fields
Added six for compatible metaclasses
Added mock because py2 doesn't have unittest.mock
Removed needless \cdot from DottedRule
Configured Travis to test on python 2.6/7 as well as 3.4
Removed py2.6 because it doesn't even have OrderedDict
Updated README to reflect py2.7 support
Merge pull request #9 from mtomwing/py2-compat

Add Python 2.7 compatibility