Allow full customization of ODL RPM repo

Allow full customization of ODL RPM repo

Instead of assuming ODL's RPM should be installed from a CentOS CBS
repo, allow installing from any repo. This will allow us to install from
ODL's new fully-CD Nexus repos.

Param rpm_url is changed to be a baseurl var to configure ODL RPM .repo
config file to install from.

This is a backwards-incompatible API change.

Also now defaults to use Oxygen ODL and fixes an issue where auth tests
were failing due to odl-restconf not being available.  Although,
odl-restconf was specified in the test, it was not being loaded because
ODL does not respect subsequent changes to the karaf features file.
Therefore we need to load it during the initial ODL install.

Closes-Bug: https://jira.opendaylight.org/browse/INTPAK-11

Change-Id: Ibf49be1bf3ee780f9ca69894ffb0a1f3f5ac385c
Signed-off-by: Daniel Farrell <dfarrell@redhat.com>
Signed-off-by: Tim Rozet <trozet@redhat.com>