Add BayesDel scores to the variant data

[melissacline]

BayesDel is the new in silico prediction method selected by ENIGMA, and they request that we add the BayesDel scores to our in silico prediction tile. The first part of that is integrating the scores into our variant data. Bing Feng, the developer of BayesDel, maintains a database with pre-computed scores for all missense variants, and is adding the scores for the indel variants. See the BayesDel documentation here, and a BayesDel database [here](https://drive.google.com/drive/folders/1K4LI6ZSsUGBhHoChUtegC8bgCt7hbQlA.
A few steps:

• Get a link that will point to the latest BayesDel database, whenever it was computed. The documentation suggests that the database and the link are date-specific.