- (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken  {
    NSArray *components = [deviceToken.description componentsSeparatedByCharactersInSet:[[NSCharacterSet alphanumericCharacterSet] invertedSet]];
    NSString *token = [components componentsJoinedByString:@""];

//sent token to server
}