Added Power Policy Manager to allow invocation of all power policies

The Power Policy Manager will allow invocation of all power policies by the NRM
See Issue #11
2 jobs for power_policy_interface in 34 seconds (queued for 56 minutes and 54 seconds)
Status Job ID Name Coverage
  Test
passed #11489
py.test

00:00:25

 
  Style
passed #11490
flake8

00:00:08