(PDB-4164) update lein-parent to support snapshots
(PDB-4164) update lein-parent to support snapshots

lein-parent 0.3.1 doesn't work properly with -SNAPSHOT builds of
dependencies.

puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb