Relay always removes files in `__generated__` eventhough it has it's artifact directory set to `__genenaretd__/relay`

We have set the `artifactDirectory` to `src/__generated__/relay`, so we can use other code-generater in sibling folders (`src/__generated__/something` eg).

Relay keeps on deleting these files though whenever run it.

My guess is that it always also checks files in `**/__generated__` folders, in order to clean up behind itself eventhough I told it to put it's files somewhere else.

I did not yet test it with another folder name.