python libraries required for plotting are not compatible with latests combine

In the resonant combination we need to update combine to get a specific roof function implementation.A summary of the releases we tried attached.

When sourcing the libraries on data/software/lib/pyhton2.7/site-packages combine text2WS will fail with the following python error

 File "/cvmfs/cms.cern.ch/slc7_amd64_gcc700/external/python3/3.6.4-pafccj/lib/python3.6/re.py", line 142, in <module>
    class RegexFlag(enum.IntFlag):
AttributeError: module 'enum' has no attribute 'IntFlag'

When not sourcing, of course the plotters will fail.

The most efficient would be adapt the plotters to the dictionaries that combine now uses...