Get the Australian based Navitia tests running

This MR adds a new Navitia backend specifying the AU coverage. This allows location searches to work and fixes the current Australia based query tests.

A full description of the issue is included below:

We are currently sending a request like this, which doesn't work:

https://playground.navitia.io/play.html?request=https%3A%2F%2Fapi.navitia.io%2Fv1%2Fplaces%3Fdisable_geojson%3Dtrue%26depth%3D1%26count%3D10%26type%255B%255D%3Dstop_area%26type%255B%255D%3Dpoi%26add_poi_infos%255B%255D%3Dbss_stands%26q%3DKing%2520George%2520Square%2520Station%26

BUT if I add coverage information (coverage/au) then I get correct and working results:

https://playground.navitia.io/play.html?request=https%3A%2F%2Fapi.navitia.io%2Fv1%2Fcoverage%2Fau%2Fplaces%3Fdisable_geojson%3Dtrue%26depth%3D1%26count%3D10%26type%5B%5D%3Dstop_area%26type%5B%5D%3Dpoi%26add_poi_infos%5B%5D%3Dbss_stands%26q%3DKing+George+Square+Station


So! It seems like the coverage needs to be set.

From reading the API (https://doc.navitia.io/#coverage) there are a few options for this. We could either provide the users location in the request or add at least an "AU Navitia" option that specifies the coverage. The Navitia backend already supports coverage (although I have some fixes for that) so I think we could just add a "AU Navitia" json config file specifying coverage.

My preference would be to add a "AU Navitia" that users can pick. That way it will work without knowing the users location. It then also is probably worth adding support to provide the location to the API if we have the information (and the user is happy with it being provided).