Ensure Fog is mocked & reset properly in ChefSpec tests
Add missing Data Bag Items mocking for ChefSpec tests on EtHaproxy
Fix mocking of Fog::Compute & move stubbed methods closer to specs

* Ensure that the Data Bag Item values are identical to the built-in mocking
of `Fog::Compute`
* Move stubbing & other expectations closer to actual tests
Stub out expectation of Pingdom IPs for ChefSpec tests