Added floating margins for get_bins (#1641)
Added floating margins for get_bins (#1641)

* accomodate float bin margins

* black formatting

* using defined bin estimators

* fixed for const values

Co-authored-by: Rohit Sonker <4e22d1d2469f2bbe2c219ed03e773ae5d5a3776a@pwc.com>
arviz-devs/arviz,arviz-devs/arviz,arviz-devs/arviz,arviz-devs/arviz