refactor sqlite db to support sqlc

cmd/main.go

@@ -43,15 +43,18 @@ func main() {
 	if dbPath == "" {
 		log.Fatalf("SQLITE_DB=/path/to/nkode.db not set")
 	}
-	db := db.NewSqliteDB(dbPath)
-	defer db.CloseDb()
+	sqlitedb, err := db.NewSqliteDB(dbPath)
+	if err != nil {
+		fmt.Errorf("%v", err)
+	}
+	defer sqlitedb.Close()
 
 	sesClient := email.NewSESClient()
 	emailQueue := email.NewEmailQueue(emailQueueBufferSize, maxEmailsPerSecond, &sesClient)
 	emailQueue.Start()
 	defer emailQueue.Stop()
 
-	nkodeApi := api.NewNKodeAPI(db, emailQueue)
+	nkodeApi := api.NewNKodeAPI(sqlitedb, emailQueue)
 	AddDefaultCustomer(nkodeApi)
 	handler := api.NKodeHandler{Api: nkodeApi}