add dmidecode so facter can resolve additional facts
add dmidecode so facter can resolve additional facts

Upstream facter falls back to `dmidecode` as of:
https://github.com/puppetlabs/facter/pull/1102

After this commit, DMI facts (such as `type`) correctly resolve
on CoreOS hosts from this container.

jumanjihouse/puppet-on-coreos,jumanjiman/puppet-on-coreos