Rdkit installation

[DocMinus]

According to the author (Greg Landrum) I believe the preferred way to install RDKit is
conda install -c conda-forge rdkit
which has the advantage that way you can use Pyton versions 3.8 and higher as well.

[b-shields]

Noted, if I get a chance I can install and test edbo using this RDKit distribution. For now I am going to leave the install instructions as is to insure that everything works.