Replace + and * with | and & for logical operations

[MaxGhenis]

e.g.:

https://github.com/PSLmodels/openfisca-uk/blob/a22170e16bd85a7cfedc1bc1f50144b6a0138ea3/openfisca_uk/variables/finance/benefit/benefit.py#L133

This works because np.array(True) + np.array(True) = np.array(True), but outside of numpy, True + True = 2. pd.Series(True) + pd.Series(True) = pd.Series(True), but this throws a warning and asks to use | instead.

Replacing bool + bool with bool | bool and bool * bool with bool & bool throughout will clarify the code.