bug: provenance changes

[bpinsard]

The following bug that appeared updating my version of nipype which makes any node crash.
Do I have a wrong version of dependencies?

/home_local/bpinsard/.virtualenvs/processing_virtenv/lib64/python2.6/site-packages/nipype/interfaces/base.pyc in run(self, **inputs)
   1007             runtime.endTime = dt.isoformat(dt.utcnow())
   1008             runtime.duration = (parseutc(runtime.endTime) -
-> 1009                                 parseutc(runtime.startTime)).total_seconds()
   1010             if len(e.args) == 0:
   1011                 e.args = ("")

AttributeError: 'datetime.timedelta' object has no attribute 'total_seconds'
> /home_local/bpinsard/.virtualenvs/processing_virtenv/lib64/python2.6/site-packages/nipype/interfaces/base.py(1009)run()
   1008             runtime.duration = (parseutc(runtime.endTime) -
-> 1009                                 parseutc(runtime.startTime)).total_seconds()
   1010             if len(e.args) == 0:

[bpinsard]

ok it seems to be a python 2.7 addition, so this would change the minimum requirement for nipype to 2.7, unless we can find an alternative.