Rename email.rs to username.rs for auth server

auth/src/robocraft/mod.rs

@@ -1,10 +1,10 @@
 mod debug;
-mod email;
+mod username;
 mod steam;
 
 pub fn stage() -> rocket::fairing::AdHoc {
     rocket::fairing::AdHoc::on_ignite("robocraft", |rocket| async {
-        rocket.attach(email::stage())
+        rocket.attach(username::stage())
             .attach(steam::stage())
             .attach(debug::stage())
             .register("/", rocket::catchers![unauthorized])