Remove six usage from api module

[Victoria Martinez de la Cruz]

Manila api is still using the six library (Python 2 and 3 compatibility library). Manila is now supporting only Python 3 so the six library is no longer needed.

[Goutham Pacha Ravi (gouthamr)]

Hi Victoria,

Are you proposing that we want separate trackers for each module? We could use a blueprint instead?

Haixin started on this effort a while ago - the work stalled due to lack of reviewer attention. We can pick it up again:

https://review.opendev.org/q/topic:%22manila_remove_six%22+(status:open%20OR%20status:merged)

[Victoria Martinez de la Cruz (vkmc)]

Thanks for the feedback Goutham. Yes, I think a blueprint would be more suitable for this. I've registered the blueprint here https://blueprints.launchpad.net/manila/+spec/manila-remove-six.

We should definitely pick up Haixin work and continue from there

[Victoria Martinez de la Cruz (vkmc)]

Marking this as invalid since this will be tracked with the bp