Extend Python HGVS and UTA packages

by Meng Wang for Global Alliance for Genomics & Health

The hgvs package in python provides an easy-to-use tool to parsing, formatting and manipulating variants. However, manipulating more types of variants is needed. The package would be more useful if it could perform variant canonicalization. The hgvs package utilizes UTA database to mapping and validating variants. Things would be easier when the UTA provides a REST interface to query. This would make the UTA database more convenient to use and reduce package dependencies of hgvs.