forked python module duplicate package readline

[timmow]

After pulling in the latest upstream boxen, my manifest failed with the following

Error: Duplicate declaration: Package[readline] is already declared; cannot redeclare at /opt/boxen/repo/shared/python/manifests/init.pp:19 on node gds0443.local

This looks like its because we forked boxen/puppet-python

We should probably look at why we forked this and if we can switch back to upstream, but as I dont need python3 right now, i've removed this from my manifest for now.