add yar client support
fix sky_execute_ex missing application_instance == 0; predis emalloc error; add redis.command tag
sky_execute_ex()
fixbug for go_agent span.tags map[string]string
支持Mysqli::query(); 完善中文文档
添加中文文档;Skywalking扩展及Agent修改;添加对PHP 7.3.0+的支持