more efficient verify_doc_li func.
updated clinvar mapping.
Python 3 compatible; remove mongokit dependencies.
new mexists method; Python3 compatible; elasticsearch logging setting.
Python3 fix.
new get_variant2 and mget_variant2 method; new ESQueryBuilder class.
/variant POST request works now.
Merge branch 'master' of github.com:Network-of-BioThings/myvariant.info