Description of problem:
When trying to add a breakpoint (called a "hook" nowadays) with --pre-create, the command does nothing and no error message is printed


Version-Release number of selected component (if applicable):
python-heatclient-0.3.0.15-ge3f16db.el7.centos.noarch


How reproducible:
100%


Steps to Reproduce:
1. Install according to the sphinx docs https://repos.fedorapeople.org/repos/openstack-m/instack-undercloud/html/virt-setup.html#preparing-the-host-machine
2. Edit the file /bin/instack-deploy-overcloud and add "--pre-create Controller" to the stack-create command 
3. Run instack-deploy-overcloud


Actual results:
The command does nothing. The stack creation doesn't start. Nothing appears in the logs and no error message is dumped to the console.