Make functions for binding to events a discardableResult

Author: hamchapman

README.md

@@ -527,7 +527,7 @@ let pusher = Pusher(key: "YOUR_APP_KEY")
 
 let chan = pusher.subscribeToPresenceChannel("presence-channel")
 
-let _ = chan.bind(eventName: "pusher:subscription_succeeded", callback: { data in
+chan.bind(eventName: "pusher:subscription_succeeded", callback: { data in
     print("Subscribed!")
     print("I can now access myId: \(chan.myId)")
     print("And here are the channel members: \(chan.members)")

Source/PusherChannel.swift

@@ -62,7 +62,7 @@ open class PusherChannel: NSObject {
 
         - returns: A unique callbackId that can be used to unbind the callback at a later time
     */
-    open func bind(eventName: String, callback: @escaping (Any?) -> Void) -> String {
+    @discardableResult open func bind(eventName: String, callback: @escaping (Any?) -> Void) -> String {
         let randomId = UUID().uuidString
         let eventHandler = EventHandler(id: randomId, callback: callback)
         if self.eventHandlers[eventName] != nil {

Source/PusherSwift.swift

@@ -114,7 +114,7 @@ let CLIENT_NAME = "pusher-websocket-swift"
 
         - returns: A unique string that can be used to unbind the callback from the client
     */
-    open func bind(_ callback: @escaping (Any?) -> Void) -> String {
+    @discardableResult open func bind(_ callback: @escaping (Any?) -> Void) -> String {
         return self.connection.addCallbackToGlobalChannel(callback)
     }