- UniqueConstraintErrors will now extend from ValidationError making it possible to catch both with `.catch(ValidationError)`
-[FEATURE] Adds `{save: false}` for belongsTo relationship setters. `user.setOrganization(organization, {save: false})` will then only set the foreign key value, but not trigger a save on `user`.
-[FEATURE] When updating an instance `_previousDataValues` will now be updated after `afterUpdate` hooks have been run rather than before allowing you to use `changed` in `afterUpdate`
-[BUG] Sequelize will no longer fail on a postgres constraint error not defined by Sequelize
#### Backwards compatability changes
- When updating an instance `_previousDataValues` will now be updated after `afterUpdate` hooks have been run rather than before allowing you to use `changed` in `afterUpdate`
