Claim all failed tests related to the same setupClass failure

[rplevka]

We should figure out an efficient way of automatically claim failed tests belonging to the same class and worker.
When py.test worker gets tests assigned, it executes the setupClass fixture on the 1st test. If this one fails, it marks this and all other tests as failure with: "setupClass failed" in the errorDetails. However, only the 1st test contains stdout - thus, the current approach doesn't automatically claim the other tests, if the claiming rule relies on the stdout field.