Always pass the plan name to fernet workbook
Always pass the plan name to fernet workbook

It was using the default (overcloud) which is not necessarily the case
for every deployment.

This commit passes the TRIPLEO_PLAN_NAME environment file and derives
the value from the passed container name.

Change-Id: I2fc481336b945c88f8b6a017690773be3293a2b4
Closes-Bug: #1742655

openstack/tripleo-common,openstack/tripleo-common