ff.create_gantt uses deprecated pandas' methods and return warnings

[ricgu8086]

When executing the following code

import plotly.figure_factory as ff

fig2 = ff.create_gantt(df_total_gantt, colors=['#FF0000', '#0000FF'], index_col='Complete',
                      show_colorbar=True, bar_width=0.2, showgrid_x=True, showgrid_y=True)
fig2.show()

it is executed correctly and returns a nice plot, however, it also returns the following:

/usr/local/lib/python3.6/dist-packages/plotly/figure_factory/_gantt.py:49: FutureWarning:

.ix is deprecated. Please use
.loc for label based indexing or
.iloc for positional indexing

See the documentation here:
http://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#ix-indexer-is-deprecated

[emmanuelle]

Thank you @ricgu8086 ! We'll fix this, unless of course you would like to submit a pull request here :-).

[nicolaskruchten]

This was already patched actually and will come out in 4.5 :) See #2011