How to release

Increment the version number in project/build.scala.
sbt publishSigned
Go to https://oss.sonatype.org/#stagingRepositories and follow these instructions.
The package should be available within ten minutes, but it might take up to two hours for it to become available at https://search.maven.org/#search%7Cga%7C1%7Cg%3A%22org.capnproto%22
Make a git tag.