Apex,CSIT: Fixes slaves and other bugs

Apex,CSIT: Fixes slaves and other bugs

Changes Include:
 - Fixes phase jobs to run on the same node
 - Removes using WORKSPACE/.tmp dir for unpacking snapshot since other
   phase jobs will need access to these files.  Now just unpacks to cache
   directory
 - Fixes download for ODL.  The previous way ODL was being downloaded
   was only if a manual patch-set job was run on the ODL gerrit.  This
   patch changes the download to use the zip artifact automatically
   produced.
 - The zip artifact is converted to tar.gz and stored in /tmp/ for the
   install job to consume. Note: the conversion is done because the
   odl-pipeline install scripts only currently accept tar.gz.
 - Extra checks in install job to make sure required files exist and
   have been previously unpacked by deploy job.

Change-Id: I38aad98cac247eb4af2839811388b119079bc7ba
Signed-off-by: Tim Rozet <trozet@redhat.com>