MAINT: Use arange instead of rolling_count.
MAINT: Use arange instead of rolling_count.

It's faster, and rolling_count is deprecated.

alphaBenj/zipline,florentchandelier/zipline,Scapogo/zipline,humdings/zipline,quantopian/zipline,florentchandelier/zipline,bartosh/zipline,enigmampc/catalyst,quantopian/zipline,humdings/zipline,bartosh/zipline,alphaBenj/zipline,enigmampc/catalyst,Scapogo/zipline