commits: c955449d4d5c7ef6b2607af13df4abed778a4c61

This data as json

sha	message	author_date	committer_date	raw_author	raw_committer	repo	author	committer
c955449d4d5c7ef6b2607af13df4abed778a4c61	Drop groups associated with nans in group variable (#3406) * Drop nans in grouped variable. * Add NaTs * whats-new * fix merge. * fix whats-new * fix test	2019-10-28T23:46:40Z	2019-10-28T23:46:40Z	0c7e9e762dbfd6554e60c953bf27493047d95109	279c587273ec459ffb5192e60bf8447c05601fa5	13221727	2448579	5635139