libvmaf: v3.0.0

add --aom_ctc v6.0, enabling convert_bitdepth

libvmaf: v2.3.1

Update CHANGELOG.md

libvmaf: api v2.2.1, soname v1.1.2

vmaf/aom_ctc: add v2.0 preset option

doc/aom_ctc: update for libvmaf v2.1.1

libvmaf: api v2.1.0, soname v1.1.0

libvmaf/README: mention SIMD is x86

Update version to 1.5.3; update CHANGELOG; add instruction for new re…

…lease. (#655)