TST: dateutil 2.3

[jreback]

cc @dbew
xref #8639
appears that python-dateutil 2.3 (just release) is breaking everything on windows (linux/mac) seem to be ok

I think that the naming convention changed

[jreback]

@dbew if you can have a look at #9036 if 'mostly' fixes the problem. Their is a comparison issue w.r.t. to the _is_tz_local