implement server state/signal handling, depend on tokio-signal

src/server.rs

@@ -7,9 +7,14 @@
 mod environment;
 pub use environment::*;
 
+mod state;
+pub use state::*;
+
 mod worker_task;
 pub use worker_task::*;
+
 pub mod formatter;
+
 #[macro_use]
 pub mod rest;