Allow servos time to move before script exit

[Gadgetoid]

See: http://forums.pimoroni.com/t/pantilthat-python-py-wont-work-anymore-but-python-commandline-does-solved/5159

[Gadgetoid]

This issue still remains controversial- and hasn't had any new reports, as far as I know, since the original issues with it.

The basic premise is that the library would require a small delay - enough to facilitate servo movement -before allowing the script to exit. Delaying at exit is slightly strange, though, so perhaps we need, instead, an example that clearly indicates how to set a servo and exit, IE:

import pantilthat
import time
pantilthat.pan(90)
time.sleep(1)