Bump default version of `phusion/baseimage` to v0.9.13.
0.5.0
Merge branch 'release/0.5.0' into develop
Add support for Riak 2.0.1

This changeset adds support for Riak 2.0.1. Included as part of the 2.0
support:

- Java 7
- Package installation via PackageCloud
- riak.conf AKA Cuttlefish configuration file format support