PFS: "all commits" should not be referenced as commitSet - (Parity with core Pachyderm 2.0)

[echohack]

Hello,

This morning I discovered we are calling "all commits" a commitSet in python-pachyderm. My understanding is that in pachctl we have abandoned the idea of a commitSet. I would expect the names of the methods and their behaviors to be updated to match the new behavior of pachctl.

python-pachyderm/src/python_pachyderm/mixin/pfs.py

Line 281 in 130caca

def inspect_commit_set(

See also: #313

This was changed fairly recently (beta.2) in core Pachyderm 2.0.