puppetlabs/apt should be installed before rabbitmq

Puppetlabs/rabbitmq installs the latest puppetlabs/apt (v 1.7.0). When
attempting to subsequently install puppetlabs/apt (v 1.6.0), the
operation fails. This commits reverts the order of these two events:
puppetlabs/apt v1.6.0 is now installed first and this satsfies the
puppetlabs/rabbitmq dependency.
Install rabbitmq 3.3.5 for the beaker tests

The puppetlabs/rabbitmq (v 3.4.0 puppet module is incompatible with
rabbitmq 4.1. There is a PR open to make the puppetlabs module support
the latest version of rabbitmq:
https://github.com/puppetlabs/puppetlabs-rabbitmq/pull/250
Until a new puppetlabs/rabbitmq release comes out, we should install
rabbitmq 3.3.5 when we run the beaker tests.
Merge pull request #20 from queeno/fix_beaker_tests

Fix puppet-uchiwa beaker tests