Add reference log sym links for skylake AVX512 builds

added cleanup testing labels

added lhcb-gaudi-head label

@frodrigu FYI this has to be tested via the nighties, as it needs a slot that includes the skylake avx512 build. I've assigned it to lhcb-gaudi-head. It cannot interfere with any other build platforms..

added lhcb-head label and removed lhcb-gaudi-head label

added lhcb-gaudi-head label and removed lhcb-head label

• [2020-06-05 00:18] Validation started with lhcb-gaudi-head#2622

This has worked in that there are now less failures in the AVX512 tests.

resolved all threads

approved this merge request

merged

mentioned in commit ab19af5e