Move install bin from rpm-distro to yum

rpm-distro element was trying to install bin programs into the
image but it doesn't provide any. Move that logic into the yum
element which provides the install-packages bin.

Change-Id: Id5339fc7ffbef6327fe41f50a3e39ab30b6d0320
Check for epel before installing it

instack runs this script on a system where epel has already been
installed, which causes the yum command to fail.  Only installing
the epel-release rpm when it isn't already present addresses the
issue.

Change-Id: Ia179d7c7ed69ea5f785b5dcd16394c7663a145cc
Merge "Move install bin from rpm-distro to yum"
Preserve exit value when leaving cleanup trap

If we entered the cleanup trap due to exit with an error code we should
exit dib with an error code.

Change-Id: Iee1a05668b3239113fb91a2da0d9a66d7de4db6b
Echo that qemu-img convert is running

qemu-img convert can take a few minutes to complete, or far longer
on heavily loaded systems. Notify the user that the image is
undergoing conversion to save them just seeing END PROFILING.

Change-Id: I1ad61ce5ed011b721d48e2d12fb42ef4aa5cd1f6
Merge "Preserve exit value when leaving cleanup trap"
Move to final release of CentOS7 images

This is the final released image; it is the same one deployed in many
cloud provers such as HP and AWS.  It is also safe from all known
vulnerabilities up to its release

Change-Id: Ib8ba561662d2a98da55eb292b850dc019226dd59
svc-map requires PyYAML

svc-map requires PyYAML, so install it. It's not always installed on all base
images.

Change-Id: I7ce5325e8afa0047f67153baa1fc7d4a90196c88