Fixes: https://openedx.atlassian.net/browse/INCR-16

Extra constraints needed to be added for pytest-randomly and tornado,
both of which have dropped Python 2 support.

This reverts commit f6c215ae.

(version 1.3.4 as of this commit)

This commit is intended to close INCR-8 issue (see https://openedx.atlassian.net/browse/INCR-8 )

This upgrades DOT by reverting the revert.

This reverts commit 4d8b9c36

ARCH-180

There was an issue with migrations on sandboxes.

This reverts commit 58f6e925

This also introduces a model for persisting organization-based filters on
a per-application basis. See openedx/core/djangoapps/oauth_dispatch/docs/decisions/0007-include-organizations-in-tokens.rst
for additional details.

This reverts commit a7fa0c21.

The problem we were having with paver 1.2.4 has been fixed and so we can go back to using the mainline paver now.