Model_building - univariate_selection

[JanBenisek]

• Since AUC cannot be applied to continuous target, we need another metric. Since we want univariate selection RMSE could be used instead. Review this before continuing.
• After, extend the function with model_type which can be [classification, regression]. Then, the function returns either RMSE or AUC. The order has to be correct (we want the highest AUC, but the lowest RMSE)

  cobra/cobra/model_building/univariate_selection.py

  Line 14 in 48d8a9a

  def compute_univariate_preselection(target_enc_train_data: pd.DataFrame,

• Document and write/modify unit tests