Update setuptools and pip to parse more metadata
Update setuptools and pip to parse more metadata

The Ubuntu xenial-provided versions of setuptools and pip don't parse
all metadata present in Python packages, especially not the "minimum
required Python version" bit. More and more packages are using this
information to limit Python 3.5-support to older versions of their
packages. In this case, the problem was caused by the "zipp" package,
which is a very remote dependency of fusesoc.

Fixes #597

lowRISC/ibex,lowRISC/ibex,AmbiML/ibex,lowRISC/ibex,AmbiML/ibex,AmbiML/ibex,AmbiML/ibex,lowRISC/ibex