Drop deps on heat-cfntools.

We're meant to be using os-collect-config now, but rabbitmq-server and
nagios3 were sucking heat-cfntools in unintentionally. They should
never have depended on heat-cfntools, as it's dependencies were solely
on os-apply-config and os-refresh-config : the way those are invoked
is not their problem.

Change-Id: I3c8b92931055192a7b9220cdc5d66a2a444ae33f