disable scaladoc publishing (#974)
disable scaladoc publishing (#974)

On JDK11 with `-release 8` it crashes with:

```
[error] java.lang.AssertionError: assertion failed:
[error]   type AnyRef in java.lang
[error]      while compiling: ...
[error]         during phase: globalPhase=terminal, enteringPhase=typer
[error]      library version: version 2.12.8
[error]     compiler version: version 2.12.8
```

This is a quick workaround as we do not rely on the published
scaladoc jars for anything.
brharrington/atlas,brharrington/atlas,copperlight/atlas,copperlight/atlas,copperlight/atlas,Netflix/atlas,Netflix/atlas,Netflix/atlas,brharrington/atlas