`Learn2_new.py` trainer inheritence

[georgemilosh]

Learn2_new.py trainer should inherit more simple trainer class. This would allow greater generality and re-usability of our code, since currently it only applies to our specific project, e.g. it assumes the way data is stored and different pre-processing operations that have to be carried out, like balancing etc

[AlessandroLovo]

This work is being carried out in this issue