* Migrate "User.UpdateUpdateAt" to Sync by default
* Fixed errors in app/team.go that prevented successful build
* Reverted some changes in user_store test that caused errors in pipeline
* return of UpdateUpdateAt changed to model.AppError
* Ensured that UpdateUpdateAt in sqlstore/user_store.go returns int64 and *model.AppError, adjusted tests accordingly
* Generated mocks and ensured storetest/user_store.go had no errors
* Added require.Nil(t, err) to proper places in tests
* Added 'err' for second return value as opposed to _ in 4 UpdateUpdateAt() occurrences in storetest/user_store.go