Regressors
**Features**
- implement basic linear regression
- implement ridge regression
**Fixes**
- fix history parameter in linear regressor
Classifiers
**Features**
- implement basic logistic regression
- implement ridge classification
- implement multiclass classifier
**Refactor**
- around prediction to actual class
**Fixes**
- fix logistic cost function
Optimizers
**Features**
- implement batch gradient descent
- implement stochastic gradient descent
- implement mini-batch gradient descent
**Refactor**
- better parameter handling
Preprocessors
**Features**
- implement standardization
- implement min-max normalization
Metrics
**Features**
- implement r2 score
Selection
**Features**
- implement dataset split
Utils
**Features**
- check dataset consistency
- shuffle dataset