checking django-wiki and fixing deprecation warnings.

We upgraded these before in https://github.com/edx/edx-platform/pull/23119 along with django-countries (which released a new version just before that), but had to revert in https://github.com/edx/edx-platform/pull/23237 because of a performance regression in the admin page for EnterpriseCustomer.  We think django-countries was the culprit and have pinned it, so trying these two again by themselves.

- switches to openedx-calc from PyPI
- includes edx-rest-api-client major upgrade.

ARCHBOM-952

Update ORA to 2.6.16 | Fixes the text_response property to be more backwards-compatible with _old_ ORA blocks.

This reverts commit 140738df.

-django-babel-underscore custom version to support django>=2.2

Upgrade ORA to 2.6.12 | When fetching file URLs from keys stored in Submission records, don't break just because we encountered one missing file; there might be more, existing files after it.

* Removing deprecated rest_framework_oauth library

* removing dependecy of django-rest-framework-oauth

* removing oauth_provider from cms

This reverts commit 1f32bc63.

-Updated middleware setting to use use middleware insted of
middleware_classes
-github install of django-method-override fork to support
new style middleware in django1.11

Updating the django-rate-limit requirement.
updated the django-ratelimit to use unreleased version that supports Django 2.2

Added the link to latest master commit of GitHub for Django 2.2 support.

django-appconf bump version using commit hash for django2.2

Wiki version bump.

Updating wiki.

There was a serialization issue with one of the studio JS assets that
is rendered as a part of the edit view.