Remove useless Debug from DispatchedMessage handler type bound.

src/dispatcher.rs

@@ -29,7 +29,7 @@ impl<M, H> DispatchedMessage<M, H> {
 impl<M, H> Job for DispatchedMessage<M, H>
 where
     M: Debug + Send,
-    H: Debug + Send + MessageHandler<M>,
+    H: MessageHandler<M> + Send,
 {
     fn execute(self: Box<Self>, context: &Context) {
         if let Err(error) = self.handler.run(context, &self.message) {

src/message_handler.rs

@@ -7,7 +7,7 @@ use crate::context::Context;
 ///
 /// Message types are mapped to handler types by Dispatcher.
 /// This trait is intended to allow composing handler logic.
-pub trait MessageHandler<Message>: Debug {
+pub trait MessageHandler<Message> {
     /// Attempts to handle the given message against the given context.
     fn run(self, context: &Context, message: &Message) -> io::Result<()>;