Fix invalid key legnth issue (stephen#316), stop issue (stephen#296)

Author: amatracaru

INSTALL.md

@@ -12,7 +12,7 @@ Install latest via source
 ```
 $ git clone https://github.com/stephen/airsonos.git
 $ cd airsonos
-$ npm install -g
+$ npm install
 ```
 
 ### Platform Specific Instructions

lib/airsonos.js

@@ -50,7 +50,11 @@ class AirSonos {
   }
 
   stop() {
-    return Promise.all(this.tunnels.map(tunnel.stop));
+    var promises = []
+      for (let id in this.tunnels) {
+        promises.push(this.tunnels[id].stop())
+      } 
+      return Promise.all(promises);
   }
 }
 

lib/tunnel.js

@@ -96,8 +96,8 @@ class DeviceTunnel extends events.EventEmitter {
   }
 
   stop() {
-    this.airplayServer.stop();
-    this.icecastServer.stop();
+    if (this.airplayServer) this.airplayServer.stop();
+    if (this.icecastServer) this.icecastServer.stop();
   }
 
 }