This patch release corrects the v2 to v2.1(.1) migration for PostgreSQL data storage (#43). The only other change in this release version numbers; v2.1 users need not upgrade to this release if they are using SQLite or RethinkDB. Conversely, v2 users can skip straight to this release if they have not yet moved to v2.1.
See the v2.1 release announcements for the enhancements that were a part of that release.