Ignore the predictions folder

No need to store the .csv results from past predictions...
Modified base class model.

- Make sure the written model does not include the index
- better filename variables.
Just some comments were changed.
Changed name for visualization script.
Added more visualizations.
We can now visualize adults and children survival rate.

Code is ugly; more generic coding style would be prettier.
New model, based on gender, fare and class

This model simply follows the tutorial. There is
no testing or validation, which would be necessary
to have robust code.
Visualize the genderclass model.