[FEATURE] classification for multiclass data

[ycseong07]

Some algorithms for classification doesn't support multiclass calssification (e.g. logistic regression).

• Add modeling functions for multiclass calssification (like this)
• Note which functions support binary/multiple classification

[ycseong07]

Except for Logistic Regression, all functions currently implemented support multiclass classification.

• Add modeling functions for multiclass calssification (like this) -> Add a multinomialRegression() function to algorithms.R

• Note which functions support binary/multiple classification -> Done.

+) Modified the rocCurve() function to show the message "rocCurve()` supports only the results of the binary classification model." when multiclass classification was implemented.