Add health check route

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

src/routes/health.rs

@@ -0,0 +1,5 @@
+use http::StatusCode;
+
+pub async fn get() -> Result<StatusCode, StatusCode> {
+    Ok(StatusCode::OK)
+}

src/routes/mod.rs

@@ -1,4 +1,5 @@
 pub mod assets;
+pub mod health;
 
 use crate::{config::Config, threads};
 use axum::{
@@ -14,6 +15,7 @@ pub async fn run(
     asset_status_sender: mpsc::Sender<threads::data::asset_status::Message>,
 ) {
     let app = Router::new()
+        .route("/health", get(health::get))
         .route("/assets", get(assets::get))
         .route("/assets/:symbol", get(assets::get_where_symbol))
         .route("/assets", post(assets::add))