Bump puppetlabs-mongodb to correct config location
Auto-configure replica-set
This does the framework for replicaset configuration. However it requires that all nodes are up and running Mongo first, so if you bring up nodes one at a time, it will probably fail on the first two. It is likely to fail on the 3rd node as well, because mongo might have started, but is not actually available by the time the script runs. To fix this (before we have a cronjob to run puppet), simply do "vagrant provision mongo-1.backend"
Update README with information about starting Mongo