heroku/barnes 2 pull requests

• Add support for Puma Max threads and Spawned Jul 2
• Detect when app is using Puma Jul 24

heroku/x 2 pull requests

• go-kit/metrics/provider/librato: add CardinalityCounter wrapper type Jul 9
• histogram: replace the underling library Jul 19

heroku/heroku-confluent-buildpack 1 pull request

• use https Jul 9