Python 3.x package is missing on pypi for 4.2.0

Description

pywps 4.2.0 is upoaded to pypi:
https://pypi.org/project/pywps/

Currently we only have:

pywps-4.2.0-py2-none-any.whl

We also need the py3 package.

PyWPS needs flulf.enum on python 2.7 ... but not on Python 3.x:

pywps/pywps/_compat.py

Line 18 in 49360cc

from flufl.enum import Enum

I suppose this is not really documented in the requirements.

Environment

Steps to Reproduce

Additional Information

It looks like we can add flufl.enum also with Python 3.x, see flufl.enum version 4.1.1:
https://pypi.org/project/flufl.enum/#description

On Python 3.x it probably does nothing ... or just points to the Python 3.x Enum.

I've added a py3k wheel to https://pypi.org/project/pywps/#files.

I can create a single wheel for both Python 2 and Python 3 with:

python setup.py sdist bdist_wheel --universal
ls -l dist/
total 144
-rw-r--r-- 1 tkralidi tkralidi 75578 Dec 17 13:37 pywps-4.3.dev0-py2.py3-none-any.whl
-rw-r--r-- 1 tkralidi tkralidi 57602 Dec 17 13:37 pywps-4.3.dev0.tar.gz

Should we update PyPI with a universal wheel or leave as is and have a universal for the next release?

The Python 3.x package works ... the Python 2.7 package is missing flufl.enum:

../../../../.conda/envs/emu/lib/python2.7/site-packages/pywps/_compat.py:18: in <module>
    from flufl.enum import Enum
E   ImportError: No module named flufl.enum

This got lost in our requirements.txt.

It looks like we can install flufl.enum both for Py 2.x and Py 3.x.

Having a universal package would be nicer to handle.

Fixed/done in master. I have cut 4.2.1 which now has a universal wheel