ENH: Add Travis

Ready for review. @dengemann you'll have to activate the service hook for Travis here on Github because I don't have the authority. Build passes on my repo:

https://travis-ci.org/Eric89GXL/PyLinkParse/builds/18300012

And coverage shows up:

https://coveralls.io/r/Eric89GXL/PyLinkParse

Note I had to also implement some fixes to be 2.6/3 compatible. I think using `six.py` is overkill for us right now, since we only need a few isolated fixes. See what you think.