USERcycle: fix `identify` event name to match the frontend

https://github.com/segmentio/analytics.js-integrations/blob/9243c32c8ab04c753640f27eee4e63a0abea1209/lib/usercycle/index.js#L53
Merge pull request #194 from segmentio/usercycle/fix-identify

USERcycle: fix `identify` event name to match the frontend