fix ddl v3

dsolovianov/postgresql/DDL.sql

@@ -20,7 +20,7 @@ CREATE TABLE dsolovianov.orders (
     id			INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
     user_id		INT,
     order_date  TIMESTAMPTZ NOT NULL,
-    status		VARCHAR(20)
+    status		VARCHAR(20),
     CONSTRAINT orders_user_fk
     	FOREIGN KEY (user_id) REFERENCES dsolovianov.users(id)
 );