Fix tests for API v1.1 and run them on Travis CI

Travis CI is free to use for open source projects and can run the tests for commit and pull request. I also fixed up the tests to work with API v1.1.

You get a report like this:
https://travis-ci.org/hugovk/twitter/builds/23026463

Python 2.7 is the main build. It also runs on 2.6, 3.2, 3.3, 3.4 (3.4 will be added to Travis any day now) and pypy as allowed failures. Python Twitter Tools doesn't support P3 yet, but at least you can see the where exactly the problems are. Python 2.6 passes.

To enable Travis CI for this repo:

1. Go to https://travis-ci.org/profile
2. Do a sync
3. Turn the twitter repo on
4. Accept PR so build will be done for the merge