[WIP] Attempt to make job submission async

[oshadura]

Probably fixes: #470 cc: @bbockelm

[lesteve]

Some CI error looks genuine for example this one: https://github.com/dask/dask-jobqueue/pull/473/checks?check_run_id=1406501917.

I am not an async expert, but I would guess you need to add some await where _call is called, maybe changing the functions calling _call to async. One such function seems to be _job_id_from_submit_output, there may be others. In an ideal world, the main user-facing functions would stay synchronous so that if you get an exception it blows up in an obvious way rather than having some log message saying that an exception was never retrieved.

Full disclosure : unfortunately I don't really understand the original issue #470 ...

[guillaumeeb]

This PR is a bit old... @oshadura are you still around and up for this change?

I'm going to close this one next time I'll take a look at the activity here, unless someone updates it.

[oshadura]

@guillaumeeb sorry I was working on other things and thanks for reminder! I will definitely try to take a look in next couple of days and update/close PR.