add more info to BadValueError
special message on undefined and null
trace the location where the error is thrown
add int32 STP
fix STP null argument bug
ClientAPI: use Axios
ServerAPI: use @koa/router
FullDate: wrapped Date only class
APIPromise: enhanced Promise on api response
application/json only(multipart/*, image/*, ... are not supported)
get, post, put, delete, patch only