admit more than 2 files (see larvatagger.jl#26)

src/maggotuba/models/predict_model.py

@@ -22,7 +22,7 @@ def predict_model(backend):
     input_files = backend.list_input_files()
     # we could go and pick files in `data/interim` as well:
     input_files += backend.list_interim_files()
-    assert 0 < len(input_files) <= 2
+    assert 0 < len(input_files)
     metadata = None
     metadata_file = [file for file in input_files if file.name == "metadata"]
     if metadata_file: