* Unfortunately it seems the jdk9-only tests could not actually be compiled.
With these changes those can actually be compiled and ran again.
* Always link to jdk11 for java.* javadocs
* Update sbt-paradox-akka to fix linking to inner classes for javadoc
* 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.