Just a heads up: we've had a number of performance improvements and bug fixes merged to master since our last release, so it seems worthwhile to push another one. Unless there are objections, I'll plan on pushing 0.19.0 out of master in the near future.
And Clara 0.19.0 is released and up on Clojars! You can see the changelog for details: https://github.com/cerner/clara-rules/blob/master/CHANGELOG.md