Overhaul [1/n]

Signed-off-by: Sean Du <do4suki@gmail.com>

internal/model/user/userkey.go

@@ -0,0 +1,11 @@
+package user
+
+type UserKey struct {
+	ID     int `xorm:"id pk autoincr"`
+	UserID int `xorm:"user_id"`
+	Key    int `xorm:"key"`
+}
+
+func (UserKey) TableName() string {
+	return "user_key"
+}