Update Ubuntu archive urls.

* Updating to utopic, 14.10.
* Updating to the US serners since this is
  what Travis originally uses in the file.
* Replace the sources.list instead of updating it.
* Update valac version to 0.22.
Set a minimum version requirement for valac.

This is probably not the oldest working version, but
it's something that's known to work. Patches accepted.