Fixed Paas deployment for SBT 0.13.
Fixed Paas deployment for SBT 0.13.

Heroku Scala Buildpack for SBT 0.13 is broken in last release:

https://github.com/heroku/heroku-buildpack-scala/issues/104

This change fixes the build by forcing the latest master of the
buildpack which has the fixed.

is-hosted-by/is-hosted-by-api,rgladwell/is-aws-api