Implement first db-test using go-txdb

cmd/budgeteer/main.go

@@ -16,7 +16,7 @@ func main() {
 		log.Fatalf("Could not load config: %v", err)
 	}
 
-	q, err := postgres.Connect(cfg.DatabaseConnection)
+	q, err := postgres.Connect("pgx", cfg.DatabaseConnection)
 	if err != nil {
 		log.Fatalf("Failed connecting to DB: %v", err)
 	}