core（100课堂Golang版基础库）

用于Golang开发时的SDK调用，简化代码

功能

Name		Name	Last commit message	Last commit date
.gitignore		.gitignore
README.md		README.md
environment.go		environment.go
go.mod		go.mod
http_signature_client.go		http_signature_client.go
http_signature_client_options.go		http_signature_client_options.go
request.go		request.go
resty.go		resty.go
retry.go		retry.go
secret.go		secret.go
signature_algorithm.go		signature_algorithm.go