Allow to add a module dependency (with SemVer range validation / helpers)
Example
$ puppet-modulator metadata dep add 'ccin2p3-etc_services' '>= 2.0.0 < 3.0.0'
Example
$ puppet-modulator metadata dep add 'ccin2p3-etc_services' '>= 2.0.0 < 3.0.0'