AttributeError np._asarray_tublesafe in tseries/converter
Discovered matplotlib/axis convert_units raised AttributeError

pandas/tseries/converter.py", line 157, in convert
    values = np._asarray_tuplesafe(values)
AttributeError: 'module' object has no attribute '_asarray_tuplesafe'

It can be easily fixed by adding:
from pandas.core.common import _asarray_tuple
and change line 157 to
values =  _asarray_tuplesafe(values)
