Make neptunium an ldap and dns server

Neptunium is going to temporarily hold the 'eqiad-ldap' name
so that we can make a graceful transition from virt1000 to
eqiad-ldap.  Once labs instances are adjusted to the new
eqiad-ldap name, virt1000 will take over and neptunium will
be shut down.

Change-Id: I2766e93f0c69475095f20751493c8dc4c70b1c85