[#56341206] Add mongodb 2.0.9 and latest to ci

I have added an extra level to the hiera hierarchy such that you can
include config for the individual boxes. I have used this to set up
different versions of mongodb on each slave.

This also requires the updates I made to the alphagov/puppetlabs-mongodb
repo.
[#56341206] Add mongo labels for jenkins

Pushed the versions of mongo on each slave through to the master using
the labels parameter on swarm
Merge pull request #32 from alphagov/add-mongodb

[#56341206] Add mongodb 2.0.9 and latest to ci