Remove oset, add dependencies for bob.ip.binseg
The oset package was used in beat/beat.cmdline>.
It currently triggers a warning with Python 3.7 that the features in uses internally will not work anymore with Python 3.8.
After analysis and tests, oset is not necessary and standard python sets do the job just fine.
Hence remove it.
This MR also addresses the addition of dependencies to support bob/bob.ip.binseg>. Namely,