Get a warning about future behavior of pandas.concat

[s-pearce]

asset-management/test/test_base.py

Line 61 in 160735e

cls.bulk_data = pd.concat(bulk_dataframes)

when running nosetests I get the warning:

asset-management\test\test_base.py:61: FutureWarning: Sorting
because non-concatenation axis is not aligned. A future version
of pandas will change to not sort by default.

To accept the future behavior, pass 'sort=False'.

To retain the current behavior and silence the warning, pass 'sort=True'.

  cls.bulk_data = pd.concat(bulk_dataframes)

This should be changed to adjust for the future behavior.