heat templates : IHA enable cfn-hup

The IHA template mentions cfn-hup in several places but doesn't
actually enable it, so do so by adding the config file and crontab
entry

Change-Id: Ie852bba24a57c262a8d813d3b3fc76ba9b5e54b4
Signed-off-by: Steven Hardy <shardy@redhat.com>