Update ruby-arel-helpers to 2.9.1.
2.9.1
* Remove has_rdoc from gemspec.
2.9.0
* Add support for Rails 6.
2.8.0
* Add support for Rails 5.2.1, which changed the arity of several internal
methods that we shamelessly use.
2.7.0
* Add support for Rails 5.2.
pkgsrc change:
* Update HOMEPAGE
* Add LICENSE
* Support multiple rails.
2.6.1
* Fix homepage URL in gemspec.
2.6.0
* Add the join alias helper.
* Add ability to pass table aliases to join_association.
2.5.0
* Add license information to gemspec so it is parsed by verifiers
(@petergoldstein #31)
* Update QueryBuilder#reflect to create deep copy of builder (@wycleffsean
#32)
