Add ability to choose location

[h1divp]

If users are now able to choose their location, then the API & redis server distribution will probably need a bit more thought. We can:

1. have servers associated with geographic region (e.g. Americas/Europe/Asia) but we either have to replicate data to make them all stay in sync
2. when a user selects a regional area they might just connect to that regional server, and be expected to deal with that latency if they're far away

I'm leaning more towards 2. since I feel like more conversations will happen locally than in other regions if we ever reach some sort of scale.