warning: this `MutexGuard` is held across an `await` point
  --> src/api.rs:21:21
   |
21 |     let data = &mut data.unwrap();
   |                     ^^^^^^^^^^^^^
   |
   = help: consider using an async-aware `Mutex` type or ensuring the `MutexGuard` is dropped before calling await
note: these are all the `await` points this lock is held through
  --> src/api.rs:24:86
   |
24 |     let subdomain = subdomain::add(&data.api_client, &params.subdomain, &params.url).await;
   |                                                                                      ^^^^^
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#await_holding_lock
   = note: `#[warn(clippy::await_holding_lock)]` on by default