The compiler plugin should be fully cross-versioned

[lrytz]

Unlike scala-library.jar, the scala compiler is not binary compatible between minor releases. Therefore, compiler plugins should in principle be released with full cross versioning, and a new release is needed for every minor Scala release. See https://github.com/scalamacros/paradise/blob/2.12.8/build.sbt for example, https://search.maven.org/search?q=g:org.scalamacros.

Similar: cb372/scala-typed-holes#6, typelevel/kind-projector#15, ghik/silencer#31