Update to MorganGenerator

[paulsonak]

For at least some of our code (like dp.diversity_plots()) we get the following deprecation warning:

[14:58:16] DEPRECATION WARNING: please use MorganGenerator

We should update this code to use a MorganGenerator:

# generate ECFP fingerprints for the full dataset
from rdkit.Chem import AllChem
from rdkit.Chem import rdFingerprintGenerator
mols = [AllChem.MolFromSmiles(s) for s in df.smiles]
morgan_gen = rdFingerprintGenerator.GetMorganGenerator(radius=2, fpSize=1024)
lib_fprints = [morgan_gen.GetFingerprint(mol) for mol in mols]