Add method to simulate we are receiving postback values (botman#5)

* Add method to simulate we are receiving postback values

* Rename method and param

src/Testing/BotManTester.php

@@ -77,6 +77,18 @@ public function receives($message)
         return $this;
     }
 
+    /**
+     * Simulates that we listen for a value
+     * but we use the receives method instead.
+     *
+     * @param $value
+     * @return BotManTester
+     */
+    public function receivesValue($value)
+    {
+        return $this->receives($value);
+    }
+
     /**
      * @param $message
      * @return BotManTester