* Adjustments to pass specs on Rails 6.0.0
* Use classic autoloader instead of Zeitwerk
* Update Rails 6.0.0 deprecated methods
* Rails 6.0.0 not allowing column with integer name
* Drop freedom_patches/rails6.rb
* Default value for trigger_transactional_callbacks? is true
* Bump rspec-rails version to 4.0.0.beta2
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
