Initial Travis file

Hey @sourrust, here's a working travis config file! You should be able to just add it and enable Travis for this repo, and the rest should be done automatically.
Travis basically makes an environment where the binary `python` is wired to `python3.3`

From the build:

```bash
$ source ~/virtualenv/python3.3/bin/activate
$ python --version
Python 3.3.5
```