API docs are now always available, no more toggle to enable them.

Show Upgrade Deadline in Studio

This shows the verified upgrade deadline for the course, as a
read-only field.

DISCO-1345

BOM-422

Awais786/prod 692

BOM-438

SE-1553 conditionally run migration on CSMH Extended table

clean up toggle annotations and lint when running feature toggle report

Update edx-platform dependencies.

Fixing python3

Fixing python3

BOM-448

Python3 compatibility.

BOM-474

BOM-481

BOM-480

BOM-473

BOM-476

BOM-450

CSMH_EXTENDED is optional, so this table is not guaranteed to exist.

Added management command to populate initial history.

Feanil/more bokchoy fixes

made changes as requested

minor fixes

quality fixes

The underlying data is put into json documents that expect unicode
strings not byte strings.  In python2 lxml provided strings that were
auto coerced but in python3 it provides byte strings.

In python2 there would be some auto coercion done so that the orginal
code here works but that's not the case in python 3.

test fixes

python3 compatibility