CHANGES.md: Updated for v4.0.0-beta.1 (#2180)
CHANGES.md: Updated for v4.0.0-beta.1 (#2180)



Former-commit-id: 6b44acabae985d2819554c5c9e6ab1f239d8b125
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox