Upgrade edx-ora2 to 2.1.17

Remove unused pytest markers for Django 1.11 upgrade

Remove temp django upgrade logic

PLAT-1524: Add on_delete kwarg to ForeignKey & OneToOneFields

Update copy for password compliance message to be more clear.

Fix PDF cert gereration/regeneration and URLs.

Django 2.0 will make this field required for `ForeignKey` and `OneToOneFields`.
In previous versions the option defaulted to `models.CASCADE` when not
specified. This change should make the deprecation warnings in the current
Django version go away.

The migrations where also modified, but the changes should not cause a change in
the database schema since `models.CASCADE` was already the old default.

OAuth2 API to call XBlock handlers

s/django.core.urlresolvers/django.urls/g

Django 1.10 deprecation fix for Hackathon XIX
Addresses PLAT-1397

TE-2543 Add tox env for Python 3.5

Allow scrolling after insert/edit image in Studio

The scroll lock class `modal-open` is removed from the body when the
EditImageModal is closed using the "Close" or "X" button, but not when the
"Insert Image" button is clicked. The submit button handler now calls the
`closeImageModal` handler too so that the `modal-open` class is removed after
inserting or editing an image.

 Removed GDPR flags and usages WIP

Removed student entrance test

[ENT-692] Change the log level from Warning to Info

Add custom HTML to Course About page sidebar

Centers all login-register forms

Merge pull request #18301 from edx/testeng/bokchoy_auto_cache_update_265b7b3e8e281d3a61011363327d949cbcd150d4

Bokchoy db cache update

Upgrade studio-frontend to latest v1.10.5

use anonymous user ID when calling the edxnotes retirement endpoint

This allows course staff to add arbitrary HTML to the sidebar on the About page.

A waffle switch has been added in the course_experience app to allow enabling and disabling of this feature.

Allow our utility function to filter out course certs when asking
Credentials for a list of certificates. This way once we start
handing back course certs, the LMS won't be surprised by
assumptions about what the credentials service will give back.

Notes retirement endpoint should require trailing slash

This is because we already require trailing slashes on most of the rest
of the retirement endpoints, which are called via slumber which appends
the trailing slash by default.

LEARNER-5039: Add new notification email.

[ENT-979] Bump edX Enterprise to 0.69.0.