Update Rich Presence example

Add Windows connection and remove version dependency from Cargo.toml

examples/discord_presence/Cargo.toml

@@ -8,5 +8,3 @@ simplelog = "~0.5"
 
 [dependencies.discord-rpc-client]
 path = "../../"
-version = "^0.1"
-default-features = true

examples/discord_presence/src/main.rs

@@ -4,7 +4,10 @@ extern crate discord_rpc_client;
 use simplelog::*;
 use std::{thread, time};
 use discord_rpc_client::Client as DiscordRPC;
+#[cfg(unix)]
 use discord_rpc_client::UnixConnection as Connection;
+#[cfg(windows)]
+use discord_rpc_client::WindowsConnection as Connection;
 
 fn main() {
     TermLogger::init(LevelFilter::Debug, Config::default()).unwrap();