updates __getitem__ function to support:  * lists, tuples, arrays, and indexes.  * fixes problem with get_columns, now returns the columns in the correct order. pick 84e01b6 adds fixtures.
updates __getitem__ function to support:
 * lists, tuples, arrays, and indexes.
 * fixes problem with get_columns, now returns the columns in the correct order.
pick 84e01b6 adds fixtures.

mouradmourafiq/pandas2sklearn