Remove unneeded "extern crate" statements

src/bin/swayr.rs

@@ -1,8 +1,6 @@
 //! The `swayr` binary.
 
-#[macro_use]
-extern crate clap;
-use clap::Clap;
+use clap::{crate_version, Clap};
 use swayr::client;
 use swayr::ipc;
 

src/bin/swayrd.rs

@@ -1,8 +1,5 @@
 //! The `swayrd` binary.
 
-extern crate serde;
-extern crate serde_json;
-
 use swayr::demon;
 
 fn main() {

src/client.rs

@@ -1,5 +1,3 @@
-extern crate serde_json;
-
 use crate::ipc;
 use crate::util;
 use std::io::Write;

src/ipc.rs

@@ -1,10 +1,5 @@
 //! Extensions of swayipc types and IPC structs.
 
-extern crate serde;
-extern crate serde_json;
-extern crate swayipc;
-extern crate users;
-
 use clap::Clap;
 use serde::{Deserialize, Serialize};
 use swayipc::reply as r;