AroonIndicator from trend.py based on inadequate input

[jennerwein]

The AroonIndicator in trend.py uses close(pandas.Series) as price data input.
But the indicator arron_up() is based on N-day high. This means that arron_up() should use high(pandas.Series) as input and not close data.
Accordingly, arron_down() should use low(pandas.Series).

This means that AroonIndicator should have two pandas.Series as input (Args): high(pandas.Series) as well as low(pandas.Series).

[jennerwein]

I solved this issue in pull request #316.

[bukosabino]

Hi @jennerwein,

The last version of the library (0.10.3) implements these changes.

Thank you all!

Best,
Dario