Fixed hyperparameter optimization"

• Bug fixes: fixed hyperparameter optimization and generation of config file with optimal parameters

Bug fixes

• Bug fixes: fixed _annotate_interactomes_of_systems method's return value and fix hierarchy annotations

Fake gene importance score annotator and code refactoring

• Add annotation in hierarchy nodes of which gene have data for VNN (train)
• Add fake generator of gene importance scores in interactomes of hierarchy system (the real generator will be
  implemented in the future)

First release

• First release on PyPI.