Add support for AnalysisBaseExternals Python 2.7 and Python 3 in same environment (!29)
Resolves #4 (closed)
Unset PYTHONHOME
and PYTHONPATH
and add supporting Python .pth
file
As PYTHONHOME
and PYTHONPATH
are unset then a AnalysisBaseExternals_python2.pth
file needs to be added for the AnalysisBase Externals Python 2.7 to be used along with ROOT in the same environment as Python 3