small change to lstm argument default

Author: nickdrhodes

code/algorithm/modules/lstm.py

@@ -6,7 +6,7 @@
 class BiLSTM(nn.Module):
     """BiLSTM which predicts multiple labels from caption data."""
 
-    def __init__(self, classes, threshold, embeddings_dim=100,
+    def __init__(self, classes, threshold=0.5, embeddings_dim=100,
                  hidden_size=128):
         """Initialise the BiLSTM.