Don't create govuk::app:envvar's when removing an app.
Don't create govuk::app:envvar's when removing an app.

Otherwise puppet will attempt to create the corresponding files in a
non-existent directory and error.

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet