1022646 - remove units_path; in 2.3, it's method.
scrap manifest migration.  not worth the effort.
download manifest to a separate path.
Merge (-s ours) pulp-2.2 => pulp-2.3, post-build
Merge pull request #710 from pulp/jortel-1022646

1022646 - nodes manifest migration fails on 2.2 to 2.3 upgrades
Automatic commit of package [pulp] release [2.3.0-0.30.beta].
Automatic commit of package [pulp-nodes] release [2.3.0-0.30.beta].
Merge (-s ours) pulp-2.3 => master, post-build