make `sbt test` launch scalahost tests
make `sbt test` launch scalahost tests

We have a customization of root/test that prevents it from aggregating
new projects automatically. Unfortunately, I forgot about that.

scalameta/scalameta,scalameta/scalameta,xeno-by/scalameta,scalameta/scalameta,MasseGuillaume/scalameta,scalameta/scalameta,olafurpg/scalameta,DavidDudson/scalameta,xeno-by/scalameta,olafurpg/scalameta,olafurpg/scalameta,scalameta/scalameta,MasseGuillaume/scalameta,DavidDudson/scalameta,xeno-by/scalameta,MasseGuillaume/scalameta