Ensure prompt_toolkit is less than version 3.0

[Matt-Haugh]

prompt_toolkit versions >= 3.0 use the asyncio event loop natively, rather then using its own implementations of event loops. This causes the import statement on line 11 of ui.py in faculty-sync to fail. To prevent this from happening I have changed the requirements file to ensure the prompt_toolkit version is less than 3.0.

Alternatively, we could follow the solution suggested in the prompt_toolkit docs:

from prompt_toolkit import __version__ as ptk_version

PTK3 = ptk_version.startswith('3.')

if PTK3:
    from asyncio import get_event_loop
else:
    from prompt_toolkit.eventloop import get_event_loop

[pbugnion]

Thanks, this looks great!

I'll release this in the next few days.

[srstevenson]

Should we do this in setup.py too?

[Matt-Haugh]

Good shout, I'll submit a PR tomorrow.