Added monitoring, limited concurent connections (#245)

* reduced the default, and added environment override.

* Using parse is more stable and doesn't fail CI this time :P

* Added support for monitoring
This support is currently basic, but it can be improved later down the road.

* Forgot scheduler file

* Added health check

* Cargo fix

* Update cargo.lock to avoid action fails.

Co-authored-by: Geometrically <18202329+Geometrically@users.noreply.github.com>

src/routes/mod.rs

@@ -18,11 +18,13 @@ mod users;
 mod version_creation;
 mod version_file;
 mod versions;
+mod health;
 
 pub use auth::config as auth_config;
 pub use tags::config as tags_config;
 
 pub use self::index::index_get;
+pub use self::health::health_get;
 pub use self::not_found::not_found;
 use crate::file_hosting::FileHostingError;