Implement Lipinski descriptors and checker

There is famous [Lipinski's rule of five](https://en.wikipedia.org/wiki/Lipinski%27s_rule_of_five), that allows to quickly estimate "druglikeliness" of the molecule.

We need to implement method that checks if a compound satisfies all 5 criterias and return boolean value. Also there are additional Lipinski descriptors that could be used in predicting molecular properties:

1. Ratio of SP3 hybridized carbons.
2. Number of aliphatic cycles (cycles that contain non-aromatic bonds).
3. Number of aliphatic heterocycles (cycles that contain non-aromatic bonds and non-carbon atoms).
4. Number of aromatic rings.

We need to implement this decriptors and add unit tests for them.