[Microbit-Python] importing modules using uflash

[hot.toast]

I'm trying to test the micropython sheduler module "usched.py" on the 
microbit.

The script I am using to test it "roundrobin.py" contains the line "from 
usched import Sched"

If I flash the microbit using the command uflash roundrobin.py, I get an 
ImportError stating no module named 'usched'

How do I get uflash to recognise that it needs to incorporate a module 
in the same path as the script?