Add download method of Http\Coroutine\Client.
Add download method of Http\Coroutine\Client.

swoole/swoole-src,LinkedDestiny/swoole-src,LinkedDestiny/swoole-src,LinkedDestiny/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,LinkedDestiny/swoole-src,LinkedDestiny/swoole-src,LinkedDestiny/swoole-src,LinkedDestiny/swoole-src