Add support for tox (http://tox.testrun.org/) and Travis CI (http://travis-ci.org/)

[msabramo]

Successful Travis CI run: http://travis-ci.org/#!/msabramo/pyrasite/jobs/1690081

To set up Travis CI for your own repo, see http://about.travis-ci.org/docs/user/getting-started/

Output of tox:

marca@ubuntu:~/dev/git-repos/pyrasite$ sudo tox 2>&1 | tee tox.out
...
___________________________________ summary ____________________________________
  py26: commands succeeded
  py27: commands succeeded
  congratulations :)

[lmacken]

Thanks Marc!