Add the beginning of a migration process for spacewalk to katello.

This patch introduces the initial portions of an migration process for spacewalk to katello. A new command, sw-export, is introduced which can pull data out of spacewalk into CSV or JSON files. Mapping files are used to transform the data as it is extracted. The existing cli is enhanced with import actions which can do idempotent imports into katello.

The typical process would be for a usr to export the data using a command such as:

sw-export orgs -s [SERVER] -u [USERNAME] -p [PASSWORD] --org-mapping-file [PATH]

and then import it with

katello -u [USERNAME] -p [PASSWORD] org import --import-file [PATH_FROM_ABOVE]

Some notes:
* importing is idempotent, so it can be run over and over.
* importing is additive, it will not delete data which was added manually
* the sw-export can store all configs in a file to make is easier to re-run the import
* the sw-export command is based off of okaara
* the sw-export is a new package, so it does not need to be installed