Fixes #11 - add device id in response

Author: ericchung

src/main/java/com/currencyfair/onesignal/model/player/ViewDeviceResponse.java

@@ -22,13 +22,25 @@
  * Response class for {@link com.currencyfair.onesignal.OneSignal#viewDevice(String, String, String)} request.
  */
 public class ViewDeviceResponse extends Device {
+    /**
+     * The device's OneSignal ID
+     */
+    private String id;
 
     /**
      * If {@code true}, this is the equivalent of a user being <i>Unsubscribed</i> (as seen in All Users).
      */
     @JsonProperty("invalid_identifier")
     private Boolean invalidIdentifier;
 
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
     public Boolean getInvalidIdentifier() {
         return invalidIdentifier;
     }