Add back button to QR Reader page

Reviewed-on: #5

Fix bugs created after changing endpoints for tests
Build for iOS

Reviewed-on: #4

Reviewed-on: #3

Todo: Save image on server for conversations & profiles

Reviewed-on: #2

Add change password page and route
Add disappearing messages page and route
Add the ability to change the server URL
Update the look and feel of the qr code

TODO: Change server URL on login. This will only affect new devices with
existing users, so will be done later.

Add change password screen and endpoint

Reviewed-on: #1

Fix "No Friends" flickering on tab change

Added custom error message for when interactions fail

WIP - Creating conversations