changelog update for persistence @0.3.0

To test persistence@0.3.0

/cc @zendesk/zendesk-radar


### Steps to merge
 - [ ] :+1: of the team
 - [ ] Merge https://github.com/zendesk/persistence/pull/3

### References
 - Jira link: https://zendesk.atlassian.net/browse/RADAR-354
https://github.com/zendesk/persistence/pull/3

### Risks
 - Radar does not start; connect to sentinel/redis correctly