Provide method name to TaskInterface

[m-hume]

allows for the task object to take the form

class myTask implements TaskInterface {
    protected $_data;
    public function run($methodName='')
    {
        if(method_exists($this, $methodName)){
            return call_user_func_array(array($this, $methodName), $this->_data);
        }
        return false;
    }

    public function setData(array $data)
    {
        $this->_data = $data;
    }

    protected function myMethodThatReceivesTheDataSetAsParameters($param1, $param2)
    {
        echo "$param1 \n";
        echo "$param2 \n";
    }
}

[coveralls]

Coverage remained the same at 56.604% when pulling 0ef9851 on m-hume:patch-2 into 144777b on anorgan:master.