The errors are raised in the runner model and in the runner connection
class. In the submission controller the errors are rescued and,
depending on the error, the status timeout / container depleted is
sent to the client.
The old approach was to require the runner connection. This did
not work anymore with Zeitwerk in Rails 6. @sebastian.serth and I
moved the Connection class in `lib` into the ActiveRecord class
`Runner`. This will also work with future changes like specific
error classes. Furthermore the config was fixed and simplified.
Co-authored-by: Sebastian Serth <Sebastian.Serth@hpi.de>
