Make python GenomeReference lazy (#2534)
Make python GenomeReference lazy (#2534)

* Make python GenomeReference lazy

* addressed comments

* fixed regex

* removed _par_jrep

* Revert "fixed regex"

This reverts commit 99bd6b5f287a971acdbf120ae0a46c75683e7275.

hail-is/hail,cseed/hail,cseed/hail,hail-is/hail,danking/hail,hail-is/hail,danking/hail,cseed/hail,cseed/hail,danking/hail,danking/hail,cseed/hail,cseed/hail,hail-is/hail,hail-is/hail,danking/hail,cseed/hail,danking/hail,danking/hail,hail-is/hail,cseed/hail,hail-is/hail,danking/hail,hail-is/hail