`utils.CPC()` needs attention

[jGaboardi]

• utils.CPC() needs attention

NCY = np.sum(Y)  # noqa: F821 Undefined name `Y` <<<<<

https://github.com/jGaboardi/spint/blob/821b62b416eb22081fae78ae70a22006be0157b0/spint/utils.py#L28

https://github.com/jGaboardi/spint/blob/821b62b416eb22081fae78ae70a22006be0157b0/spint/__init__.py#L10

https://github.com/jGaboardi/spint/blob/821b62b416eb22081fae78ae70a22006be0157b0/spint/utils.py#L14-L31