If the playbook is run multiple times or a host already has
swap configured, re-adding swap over the existing file
will cause untold problems. Also, it will not persist across
reboots unless added to fstab.
Avoid this by checking if any swap is active. If not
create a unique swapfile and format it. Then enable
it to persist across reboots.
Signed-off-by: Chris Evich <cevich@redhat.com>