Warning Received from the build_drug_desc.py script. Adding to v2.2 mainly because I am getting about 50k lines of this in the build logs and its making searching for other issues / debugging more difficult (but it is not absolutely required for v2.2).

[10:58:49] DEPRECATION WARNING: please use MorganGenerator
[10:58:49] DEPRECATION WARNING: please use MorganGenerator
[10:58:49] DEPRECATION WARNING: please use MorganGenerator