Rename generator to polymorphic_resource_owner

[ci skip] Update changelog

Merge pull request #13 from nbulaj/4.4.x_compatible

4.4.x compatible

Update to upstream, specs, fixes

* Update to Doorkeeper upstream
* Fix various issues
* Test against Rails 5.2
* Bump version

Merge pull request #9 from nbulaj/sequel_fix

Fix Sequel database error for non-existing tables

Allow using of Sequel 5: merge pull request #8 from nbulaj/sequel5

Allow to use Sequel 5

[ci skip] README update

Bump gem version

Merge pull request #3 from nbulaj/refactoring

1.2.1

Merge branch 'master' of https://github.com/nbulaj/doorkeeper-sequel