small tweaks

Source/SocketEngine.swift

@@ -332,7 +332,7 @@ public final class SocketEngine: NSObject, SocketEngineSpec, WebSocketDelegate {
                     createWebsocketAndConnect(true)
                 }
                 
-                client?.engineDidOpen("Connect")
+                client?.engineDidOpen?("Connect")
             }
         } catch {
             DefaultSocketLogger.Logger.error("Error parsing open packet", type: logType)

Source/SocketEngineClient.swift

@@ -28,7 +28,7 @@ import Foundation
 @objc public protocol SocketEngineClient {
     func didError(reason: AnyObject)
     func engineDidClose(reason: String)
+    optional func engineDidOpen(reason: String)
     func parseEngineMessage(msg: String)
     func parseEngineBinaryData(data: NSData)
-    func engineDidOpen(reason: String)
 }

Source/SocketIOClient.swift

@@ -318,10 +318,6 @@ public final class SocketIOClient: NSObject, SocketEngineClient, SocketParsable
         }
     }
     
-    public func engineDidOpen(reason: String) {
-        didConnect()
-    }
-    
     // Called when the socket gets an ack for something it sent
     func handleAck(ack: Int, data: [AnyObject]) {
         guard status == .Connected else {return}