Init V4 community edition (#2265)

* Init V4 community edition

* Init V4 community edition

application/migrator/model/setting.go

@@ -0,0 +1,13 @@
+package model
+
+import (
+	"github.com/jinzhu/gorm"
+)
+
+// Setting 系统设置模型
+type Setting struct {
+	gorm.Model
+	Type  string `gorm:"not null"`
+	Name  string `gorm:"unique;not null;index:setting_key"`
+	Value string `gorm:"size:65535"`
+}