Only use specific repos

[greg-freewave]

The docs specify to configure otp_app when configuring Wallaby and then Wallaby will automatically infer all of your repos and configure them to use the sandbox. Some of our repos do not support the sandbox and so allowing Wallaby to handle all of them doesn't work for us. The work around that we have found is to create a dummy "otp_app" config and pass that to wallaby like so:

config :my_dummy_app, ecto_repos: [RepoSupportingSandbox]

config :wallaby, otp_app: :my_dummy_app

This seems to solve the problem but is rather clunky, is there some other way to specify to Wallaby exactly which Repos it should handle for the sandbox checkout?