add location params to POST streams/:id/

[hburgund]

Per RW API V2, both latitude and longitude need to be sent as POST params in POST streams/:id.

This is of crucial importance for geo-listen-enabled projects as it allows the stream to set the speaker volumes properly as well as determine if the listener is in range for the project.

It is also required even when geo-listen-enabled is false (this is admittedly not intuitive, but it's a thorny issue on the server and since we are pushing towards client-side mixing, is not worth the effort to figure out and fix). Sending the default location of 1/1 will be fine, though the best solution would be to send the project default location taken from the response to GET projects/:id/ - https://roundware.org/api/#get-projects-id. No need to worry about the latter solution unless it is no harder to do than the former.