Warnings from pandas

[lnksz]

I will collect here the raised warnings from pandas.

in main.rivus.create_model()

• [x] line 94 & 169: sortlevel is deprecated.
• [x] line 145: Boolen Series will be reindexed
• [x] in def multiply_by_area_demand

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

• [ ] df.convert_objects(convert_numeric)

FutureWarning: convert_objects is deprecated. 
Use the data-type specific converters pd.to_datetime, pd.to_timedelta and pd.to_numeric.
  df = df.convert_objects(convert_numeric=True)