OPT: detect_vertebral_levels: now upper disc added
OPT: detect_vertebral_levels: now upper disc added

Former-commit-id: 56639bec194cac0ef6f701060717147db021f5a8 [formerly 4e73ad81b9bc66df76155a52e2ceee38625ea938]
Former-commit-id: 0e1a9b8d95e99b531fb9dbaa77c5cfa9e975f660
Former-commit-id: c16611ff71695e28eb7a4f15ff27b281f7691197
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox