utils.py:line94, .ix is deprecated resulting in FutureWarning

[neilsmurphy]

FutureWarning error in the utils.py module at line 94 in the rebase function.

Pandas' .ix is now deprecated and a simple change to .iloc[0] in the rebase function fixes this. I've run this in isolation and tested against both series and dataframe timeseries prices and it works well.

[ranaroussi]

Fixed in 0.0.24