prospector dependencies break with new pylint2.0.0 and pyflakes 2.0.0

[JensTimmerman]

when installing prospector on a clean system I'm getting dependency conflicts:
pkg_resources.ContextualVersionConflict: (pyflakes 2.0.0 (/Users/jenstimmerman/workspace/vsc-install/.eggs/pyflakes-2.0.0-py2.7.egg), Requirement.parse('pyflakes<1.7.0,>=1.5.0'), set(['flake8']))

My current workaround is to install an older pylint and pyflakes <2.0.0 before installing prospector

[JensTimmerman]

flake8 has requirements on pyflakes<1.7.0,>=1.5.0
but prospector has a requirement on 'pyflakes>=0.8.1'
so setuptools first installs pyflakes>=0.8.1, (which is 2.0.0 now) which then breaks the flake8 install
https://gitlab.com/pycqa/flake8/blob/master/setup.py#L24