Fix test failure line reporting

When using the parallel role, the runtest method gets wrapped with Moose
'around' resulting in roughly 4 levels of wrapped code.
Test::Builder needs to be told that the failure doesn't come from
Test::Class::Moose:Role::Parallel
Merge pull request #28 from shumphrey/fix-some-builer-report-levels

Fix test failure line reporting with Role::Parallel