Erroneous Maidenhead locator for longitudes > 180˚

[stroobandt]

Consider the following US location 37°N 80°W:

import maidenhead as mh
mh.to_maiden(37, -80)
'FM07aa'

Which for scientific applications can also be expressed in solely positive degrees as 37˚N 280°E:

mh.to_maiden(37, 280)
'XM07aa'

Thank you in advance for fixing this error.

Conversely, an option for to_location to output solely positive longitudes would also be well appreciated.