ENH: add buyback_auth dataset.
ENH: add buyback_auth dataset.

humdings/zipline,wilsonkichoi/zipline,florentchandelier/zipline,enigmampc/catalyst,alphaBenj/zipline,Scapogo/zipline,florentchandelier/zipline,enigmampc/catalyst,magne-max/zipline-ja,wilsonkichoi/zipline,bartosh/zipline,quantopian/zipline,alphaBenj/zipline,bartosh/zipline,magne-max/zipline-ja,umuzungu/zipline,humdings/zipline,umuzungu/zipline,Scapogo/zipline,quantopian/zipline