add support for setting INHERIT_DATASTORE_ATTRs

[jtriley]

This adds support for setting INHERIT_DATASTORE_ATTR settings in oned.conf, e.g.:

one::oned::inherit_datastore_attrs:
  - 'DRIVER'

[jtriley]

@rwaffen Tests pass now - FYI existing $hook_scripts iteration in your oned.conf.erb template would fail the same way this PR did provided you didn't specify the setting at all in test.yaml hiera config and you're using ruby >= 1.9. This is due to https://projects.puppetlabs.com/issues/15329. Rather than just add a value to test.yaml hiera I set the default to empty array to avoid this issue for all versions of ruby and puppet.

[rwaffen]

oh thanks... sound like problem for not getting "real" booleans out of hiera ... we will check this for our setup... is this a ruby1.9+ only problem?

[jtriley]

@rwaffen Yep - if you look at the failed builds for this PR you'll see it passes on ruby 1.8.7 for all versions of puppet but fails on all versions of ruby >= 1.9 and all versions of puppet....