chore: add a version file includes gin version (#1549)

* chore: add a version file includes gin version

* update version for dev version

gin.go

@@ -14,11 +14,7 @@ import (
 	"github.com/gin-gonic/gin/render"
 )
 
-const (
-	// Version is Framework's version.
-	Version                = "v1.3.0"
-	defaultMultipartMemory = 32 << 20 // 32 MB
-)
+const defaultMultipartMemory = 32 << 20 // 32 MB
 
 var (
 	default404Body   = []byte("404 page not found")

version.go

@@ -0,0 +1,8 @@
+// Copyright 2018 Gin Core Team.  All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package gin
+
+// Version is the current gin framework's version.
+const Version = "v1.4.0-dev"