UI Testing and Predicting with a model crashes silently

[JulienVig]

When a model has been trained, one can test it and use it to predict new data. Both fail silently with the error TypeError: e.size is not a function in the console.

To Reproduce
Steps to reproduce the behavior:

1. Train or download a titanic model
2. Click on Test (or Predict)
3. Upload train.csv or test.csv
4. Click on Test (or Predict)

Expected behavior
Testing a model should yield the test accuracy as well as the number of samples visited. Predicting with a model should display the resulting predictions and let the user download them.