New Travis Listener Service

Hi all,

I just put online a new version of the Travis Listener: https://travis2.durieux.me (the main dashboard is mainly there to ensure that the service is working properly).
The websocket is available at the following address: `wss://travis2.durieux.me`.

The difference with the previous version is that there are new events:
1. build
2. build_updated
3. build_finished

And also the messages contain more information such as
- the repository information
- the user information
- the longitude, latitude of the user place

The new information is only available if I succeed retrieve it from GitHub (token limitation).

I will also try to include the diffs.

I hope some of you will find it useful!