Merge branch 'lukas_issue311_bug_fileexistserror-in-cleanup' into 'develop'

Resolve "FileExistsError in Cleanup / DataHandler Build"

See merge request !305

mlair/data_handler/default_data_handler.py

@@ -79,7 +79,7 @@ class DefaultDataHandler(AbstractDataHandler):
     def _cleanup(self):
         directory = os.path.dirname(self._save_file)
         if os.path.exists(directory) is False:
-            os.makedirs(directory)
+            os.makedirs(directory, exist_ok=True)
         if os.path.exists(self._save_file):
             shutil.rmtree(self._save_file, ignore_errors=True)