Enabled building for Travis CI

This enables building on Travis CI for the develop branch and once we merge it to master we'll have it there as well. It's build with gcc and clang as an example using the versions available. This is something we need to adjust going forward so it's built with what we care about.

As few thing to note though:

1) In the readme file is a reference to the build status which needs to be changed to refer to master when merging with master.

2) There's an example for integrating Travis building status with IRC that I added at the end of the .travis.yml file. Take a look and enable if you think this could be a good thing.

3) Finally we need to enable building of the repo on www.travis-ci.org.