change sled to sqlite and remove lic

src/lib.rs

@@ -1,6 +1,6 @@
 mod rendezvous_server;
-mod sled_async;
 pub use rendezvous_server::*;
-use sled_async::*;
+pub mod common;
+mod database;
+mod peer;
 mod version;
-pub use version::*;