context.go
func (ctx *Context) GetFile(name string) (multipart.File, *multipart.FileHeader, error) {
	return ctx.Req.FormFile(name)
}
func (ctx *Context) GetFile(name string) (multipart.File, *multipart.FileHeader, error) {
	return ctx.Req.FormFile(name)
}
// GetFile returns information about user upload file by given form field name.