Allow devstack to build ironic agent ramdisk

This provides a way to test Ironic-python-agent code that is
not yet merged.

Change-Id: I85084c383263173a33250592a95a17f46827b347
Fix another_role variable for swift

An error occurs because ANOTHER_ROLE variable in lib/swift is not set.
This patch gets and sets the value to another_role variable.

Change-Id: I9d67ce243eb6bb42ed7e3522ef816295847d48fa
Closes-Bug: #1363884
Merge "Fix another_role variable for swift"
Merge "Allow devstack to build ironic agent ramdisk"
Merge branch 'master' of https://github.com/openstack-dev/devstack