Increase test coverage for deleting all inventory for a
resource provider. These new tests check if the inventory
was deleted for both DELETE and PUT methods, and check if
the new resource generation has been correctly updated as
expected.
The DELETE method is implemented by the following change:
I1ecb12c888f873e8330367c8411d5a2ef0458495.
These tests have been originally proposed in this change:
I626ca4a821b5ab0ebcaa79937a31771fbae5b8d9, however, since
these tests do not have anything about the client side code,
I broke it down into a separate change.
Change-Id: I73aff37aaecf1f3755f0445ab9edb8f6454cf6c3
7ba0b7ad5f