stuff moved to a new package. you wouldn't expect that in a point
release, but they put type aliases in place so Scala users wouldn't
notice. but the change is visible to Java code.
the upgrade is not strictly necessary, but it would be convenient
for the Scala 2.13 community build to have this merged, so I don't
have to maintain these changes in our Akka fork
* Add CopyrightHeader support for sbt-boilerplate plugin.
* Add CopyrightHeader support for `*.proto` files.
* Add regex match for both `–` and `-` for CopyrightHeader.
* Add CopyrightHeader support for sbt build files.
* Update copyright from 2018 to 2019.
