move RumaResponse out of core Error; cleanup Error conversions.

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/mod.rs

@@ -10,7 +10,7 @@ pub mod utils;
 pub mod version;
 
 pub use config::Config;
-pub use error::{Error, RumaResponse};
+pub use error::Error;
 pub use pdu::{PduBuilder, PduCount, PduEvent};
 pub use server::Server;
 pub use version::version;