Elastic net model implementation

[woohoos]

A lot of predictors that are being implemented, including those that you used in your research (like Horvath and Zhang), are implemented using R glmnet library use text or csv files to store model coefficients and intercept, it would be useful to be able to test such clocks using your package(without turning them into pickle files), especially because when including new model it is not possible to select age transformation method.