Implement keycode translation for windows (#54)

closes #48 
closes #16

src/backend/producer/dummy.rs

@@ -1,6 +1,6 @@
 use std::io;
 use std::pin::Pin;
-use std::task::{Poll, Context};
+use std::task::{Context, Poll};
 
 use futures_core::Stream;
 
@@ -32,10 +32,7 @@ impl EventProducer for DummyProducer {
 impl Stream for DummyProducer {
     type Item = io::Result<(ClientHandle, Event)>;
 
-    fn poll_next(
-        self: Pin<&mut Self>,
-        _cx: &mut Context<'_>,
-    ) -> Poll<Option<Self::Item>> {
+    fn poll_next(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         Poll::Pending
     }
 }