initial Travis CI setup

This PR integrates Travis CI.

To setup Travis for the main fifengine/fifengine repo, please login at Travis and fetch your API token from the user profile page. In the Github admin area of the fifengine repo you'll find a Github Hooks page, select Travis there, then drop that token into the hook setup dialog (just username and token + set active). After that, you might test the hook.
If the hooks works, every push to the master repo gets a build on travis.

Travis URL will be https://travis-ci.org/fifengine/fifengine/
You find detailed build logs there.
The actual build log will look like this: https://travis-ci.org/jakoch/fifengine/builds/6171810#L880

As you can see, all dependencies are fetched and the build is triggered..
There is currently no main script running.
I made a guess that some functional tests are at tests/fife_test/run.py
https://github.com/jakoch/fifengine/blob/travis-setup/.travis.yml#L13
But i don't know if they report to the console...

You will also see, if a build is successful, by looking at the build status icon, which i added to the readme. Also moved some text around - hope that's ok.

This just the inital throw - so the script needs fine-tuning. 
So for instance, you might enable reporting to your IRC channel.
It's prepared, but commented out, because i didn't want to spam the channel.

Also, big sorry! For i do not know the correct base branch for this pull request.
So i'm just using "master". Hope that's ok.

Regards, Jens