clear response listeners after 2 seconds.

lib/program.js

@@ -1383,13 +1383,20 @@ Program.prototype.response = function(name, text, callback) {
     ? 'response ' + name
     : 'response';
 
-  this.once(name, function(event) {
+  var onresponse;
+
+  this.once(name, onresponse = function(event) {
+    if (timeout) clearTimeout(timeout);
     if (event.type === 'error') {
       return callback(new Error(event.event + ': ' + event.text));
     }
     return callback(null, event);
   });
 
+  var timeout = setTimeout(function() {
+    self.removeListener(name, onresponse);
+  }, 2000);
+
   return this._write(text);
 };