* 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.
* add java support in akka-actor module in the class Abstract.ActorContext by adding the setReceiveTimeout and CancelReceiveTimeout
* add akka.actor.AbstractActor#ActorContext cancelReceiveTimeout and setReceiveTimeout to mima-excludes file
* removed scala.concurrent.duration dependency in ActorDocTest and add new method expectTerminated with java.time.Duration support in TestKit
* used java.time.Duration as default import
* Identical contents in scala/cluster-metrics.md and java/cluster-metrics.md for easier review
* Replace java/cluster-metrics.md with a symlink to scala/cluster-metrics.md
* Fix typo