Fixing SHAPley calculation and add it to DL1r integration test
Summary
This MR introduces the following changes
- Fixing an issue with the calculation of the SHAPley values. No integration test was present for that and so the bug was not detected. This is now fixed.
- Integration test for DL1r extended to also run the calculation and plotting of the SHAPley values (runs 20s longer now).
- Adapted documentation of SHAPley accordingly
Tagging @sargyrop who found the bug