refactoring integration tests

Makefile

@@ -49,6 +49,9 @@ clean:
 	rm -rf src/tools.db
 	rm -rf src/*.out
 	rm -rf src/*.prof
+	rm -rf tests/debug*.txt
+	rm -rf tests/debug*.html
+	rm -rf tests/debug*.png
 	find . -name '.sesskey' -exec rm -rf {} +
 	find . -name '.pytest_cache' -exec rm -rf {} +
 	find . -name '__pycache__' -exec rm -rf {} +