Add a http2 multi requests unit test.
Add a http2 multi requests unit test.

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