初始化项目框架，完成部分接口开发

utility/ecode/common.go

@@ -0,0 +1,17 @@
+package ecode
+
+var (
+	OK               = New(0, "success")
+	Sub              = New(1, "") // 自定义错误信息
+	Fail             = New(2, "server_error")
+	InvalidOperation = New(3, "invalid_operation")
+	Params           = New(4, "params_error")
+	Logout           = New(5, "not_login")
+	Disabled         = New(6, "account_disabled")
+	Denied           = New(7, "permission_denied")
+	Expire           = New(8, "token_expired")
+	Auth             = New(1000, "auth_failed")
+	Password         = New(1001, "password_incorrect")
+	EmailExist       = New(1002, "email_exists")
+	NotFound         = New(1003, "not_found")
+)