Starts a new task.

            `env`
                Runtime ``Environment`` instance.
            `args`
                Arguments object from arg parser.

def execute(self, env, args):
        """ Starts a new task.

            `env`
                Runtime ``Environment`` instance.
            `args`
                Arguments object from arg parser.
            """

        # start the task
        if env.task.start(args.task_name):
            env.io.success(u'Task Loaded.')