Update collections.Sequence

[e-dervieux]

Importing Sequence from collections now triggers an error in Python > 3.7, see here:

https://stackoverflow.com/questions/69596494/unable-to-import-freegames-python-package-attributeerror-module-collections

So the code in bic.py

if not isinstance(y, (collections.Sequence, np.ndarray, pd.core.series.Series)):

should be replaced by

if not isinstance(y, (collections.abc.Sequence, np.ndarray, pd.core.series.Series)):

for instance (there may be similar instances in other file from this package).