Fix autoreconnect

The reachability object was was not being retained, so it was being
deallocated right after being created.

This also stops the autoreconnect behavior if the connection is explicitly
disconnected.

Author: bdolman

Source/PusherSwift.swift

@@ -161,6 +161,19 @@ public class PusherConnection: WebSocketDelegate {
     public var channels = PusherChannels()
     public var socket: WebSocket!
     public var URLSession: NSURLSession
+    
+    public lazy var reachability: Reachability? = {
+        let reachability = try? Reachability.reachabilityForInternetConnection()
+        reachability?.whenReachable = { [unowned self] reachability in
+            if !self.connected {
+                self.socket.connect()
+            }
+        }
+        reachability?.whenUnreachable = { [unowned self] reachability in
+            print("Network unreachable")
+        }
+        return reachability
+    }()
 
     public init(key: String, socket: WebSocket, url: String, options: PusherClientOptions, URLSession: NSURLSession = NSURLSession.sharedSession()) {
         self.url = url
@@ -225,15 +238,19 @@ public class PusherConnection: WebSocketDelegate {
 
     public func disconnect() {
         if self.connected {
+            self.reachability?.stopNotifier()
             self.socket.disconnect()
         }
     }
-
+    
     public func connect() {
         if self.connected {
             return
         } else {
             self.socket.connect()
+            if let reconnect = self.options.autoReconnect where reconnect {
+                _ = try? reachability?.startNotifier()
+            }
         }
     }
 
@@ -529,30 +546,11 @@ public class PusherConnection: WebSocketDelegate {
         if let error = error {
             print("Websocket is disconnected: \(error.localizedDescription)")
         }
-
+        
         self.connected = false
         for (_, channel) in self.channels.channels {
             channel.subscribed = false
         }
-
-        if let reconnect = self.options.autoReconnect where reconnect {
-            let reachability = try! Reachability.reachabilityForInternetConnection()
-
-            if let reachability = try? Reachability.reachabilityForInternetConnection() {
-
-                reachability.whenReachable = { reachability in
-                    if !self.connected {
-                        self.socket.connect()
-                    }
-                }
-
-                reachability.whenUnreachable = { reachability in
-                    print("Network unreachable")
-                }
-            }
-
-            if let _ = try? reachability.startNotifier() {}
-        }
     }
 
     public func websocketDidConnect(ws: WebSocket) {}