Changed continuous-servo ccw value to 0

[ericterpstra]

A value of 89 is not far enough from the rest point to move the servo. Because 180 is the extreme value for the clockwise rotation, I think it makes sense to set counterclockwise to the opposite extreme - this provides uniform rotation in either direction.

This addresses issue #33

[edgarsilva]

Looks good, but some tests are failing, can you pls update, if not I'll do it later today and merge.

@ericterpstra thanks for the fix :+1: :exclamation:

[ericterpstra]

Sorry about that, I'm pretty new at this. I can fix it later this evening 😬

[deadprogram]

Looks good! Merging...