tie weights in masked lm (#455)

Summary:
Pull Request resolved: #455

Tie word embedding weights with output layer weights

Reviewed By: kartikayk

Differential Revision: D14686543

fbshipit-source-id: fc15f756b1043b6ab7b208b43442c5c13ef402ea

pytext/workflow.py

@@ -109,7 +109,7 @@ def prepare_task(
         set_random_seeds(config.random_seed)
 
     if config.load_snapshot_path and os.path.isfile(config.load_snapshot_path):
-        task = load(config.load_snapshot_path)
+        task, _ = load(config.load_snapshot_path)
     else:
         task = create_task(config.task, metadata=metadata)