Testutils for reports should munge resource events to a set

The order of the resource events returned by an event query
does not guarantee order; thus, we need to munge the results
into a set before we do comparisons in tests.
Merge pull request #504 from cprice-puppet/maint/master/munge-resource-event-vec-to-set-for-tests

Testutils for reports should munge resource events to a set