Feat/fileserver (#60)

* cleanup code for URL type

* fix makefile for trace mode

* refactor, merge Entry, RawEntry and Route into one. 

* Implement fileserver.

* refactor: rename HTTPRoute to ReverseProxyRoute to avoid confusion

* refactor: move metrics logger to middleware package

- fix prometheus metrics for load balanced routes
  - route will now fail when health monitor fail to start

* fix extra output of ls-* commands by defer initializaing stuff, speed up start time

* add test for path traversal attack, small fix on FileServer.Start method

* rename rule.on.bypass to pass

* refactor and fixed map-to-map  deserialization

* updated route loading logic

* schemas: add "add_prefix" option to modify_request middleware


* updated route JSONMarshalling

---------

Co-authored-by: yusing <yusing@6uo.me>

internal/net/http/accesslog/access_logger_test.go

@@ -9,7 +9,6 @@ import (
 	"testing"
 	"time"
 
-	E "github.com/yusing/go-proxy/internal/error"
 	. "github.com/yusing/go-proxy/internal/net/http/accesslog"
 	"github.com/yusing/go-proxy/internal/task"
 	. "github.com/yusing/go-proxy/internal/utils/testing"
@@ -30,7 +29,7 @@ const (
 
 var (
 	testTask = task.RootTask("test", false)
-	testURL  = E.Must(url.Parse("http://" + host + uri))
+	testURL  = Must(url.Parse("http://" + host + uri))
 	req      = &http.Request{
 		RemoteAddr: remote,
 		Method:     method,