Update app.py

app.py

@@ -20,7 +20,7 @@ for f in ['checkpoint', 'checkpoint.data-00000-of-00001', 'checkpoint.index']:
     path = '/'.join(temp_value)
     os.rename(old_name, os.path.join(path, f))
 
-latest = tf.train.latest_checkpoint('cache_dir')
+latest = tf.train.latest_checkpoint(cache_dir)
 hypermodel = MakeHyperModel(input_shape=IMAGE_SIZE + (3,), num_classes=2, data_augmentation=data_augmentation)
 model = hypermodel.build(hp=HyperParameters())
 model.load_weights(latest).expect_partial()