Merge pull request heroku#144 from heroku/malax/update-sbt-extras

Update sbt-extras

Merge pull request heroku#144 from heroku/malax/update-sbt-extras

Update sbt-extras

Merge pull request heroku#141 from heroku/sbt-1.3-cache

Clean sbt cache dir from slug

Merge pull request heroku#141 from heroku/sbt-1.3-cache

Clean sbt cache dir from slug

Merge pull request heroku#137 from heroku/cache-sys-props

Pass cache to JVM install to cache system.properties file

Merge pull request heroku#135 from heroku/export-sbt

Add export script so that subsequent buildpacks can use sbt

Merge pull request heroku#133 from heroku/jamesward-patch-1

Ensure bash

Merge pull request heroku#130 from heroku/jvm-url

 Use registry URL to fetch JVM buildpack

Added new publish script and buildpack.toml

More universal bash in hatchet setup script