Update to mio 0.7, remove mio-extras (#278)

Cargo.toml

@@ -32,8 +32,7 @@ walkdir = "2.0.1"
 
 [target.'cfg(target_os="linux")'.dependencies]
 inotify = { version = "0.8", default-features = false }
-mio = "0.6.15"
-mio-extras = "2.0.5"
+mio = { version = "0.7.7", features = ["os-ext"] }
 
 [target.'cfg(target_os="macos")'.dependencies]
 fsevent = "2.0.1"

src/error.rs

@@ -145,13 +145,6 @@ impl<T> From<std::sync::PoisonError<T>> for Error {
     }
 }
 
-#[cfg(target_os = "linux")]
-impl<T> From<mio_extras::channel::SendError<T>> for Error {
-    fn from(err: mio_extras::channel::SendError<T>) -> Self {
-        Error::generic(&format!("internal channel error: {:?}", err))
-    }
-}
-
 #[test]
 fn display_formatted_errors() {
     let expected = "Some error";