Using categories instead of n_values

[isaacguerreir]

The OneHotEncoder object can be created using n_value or categories as parameters. But the use of n_values was deprecated and will be removed in version 0.22. Using n_value is more intuitive for this example, but in the future will be necessary modify n_value to categories.

I make a copy of this notebook and change n-value to categories='auto'. The notebook run without any error.