v0.2.1 Release

Release 0.2.1

v0.2

add coro_io, struct_xml, struct_json, struct_yaml.

v0.1.1

add coro_http_client；
coro_rpc support custom serialization protocol, custom route, custom rpc protocol;
struct_pack support span;
some bug fix;

The first version of yalantinglibs

This version contains such libs:

1. rpc lib(coro_rpc)
2. serialization libs(struct_pack, struct_pb, struct_json)
3. coroutine lib(async_sumple)
4. log lib(easylog)