func NewHTTPMiddleware(next http.Handler, logger log.Logger) *HTTPMiddleware {
	return &HTTPMiddleware{next, logger}
}
NewHTTPMiddleware wraps an http.Handler and a log.Logger,
and performs structured request logging.
package ctxlog
import (
	"net/http"
	"time"
	"github.com/go-kit/kit/log"
)
type HTTPMiddleware struct {
	next   http.Handler
	logger log.Logger
}