No longer base64 encode the private ssh key

tripleo-incubator is now expecting it unaltered.

Change-Id: I02b355583aa5380e2791976a222fae4c98cff34c
Add power_manager and arch to the test env json

When Ia373cd2007750a2ce5ad0b1ee18cf3c44591d9dc merges tripleo-incubator
will be expecting these.

Change-Id: I04e55a078e95381af693f0264d2dd3a880b9ff68
Merge "No longer base64 encode the private ssh key"
Merge "Add power_manager and arch to the test env json"