Code update for new Tuskar API

* Currently uses mock data
* Many tests have call_count asserts removed
* Many tests are removed pending additional API refactoring
* Plan creation workflow needs to be fixed; successive
  workflow steps depend on initial role-selection step
* Overcloud and plans index redirect logic may need to be rethought
* Plans need to take responsibility for image and flavor (instead of
  role)

Change-Id: I3299a66b4f11b74196d88c458b276cad0851cbab