Simplify saving, when parent folder doesn't exist.

Author: Miltos Allamanis

ptgnn/baseneuralmodel/abstractneuralmodel.py

@@ -151,6 +151,7 @@ def build_neural_module(self) -> TNeuralModule:
 
     # region Saving/Loading
     def save(self, path: Path, model: TNeuralModule) -> None:
+        os.makedirs(os.path.dirname(str(path)), exist_ok=True)
         with gzip.open(path, "wb") as f:
             torch.save((self, model), f)