Add better http error handling to award program certificate

Upgrade Django to 1.11.15 in base.in as well

Update gunicorn slightly.

TE-2524 Stop using nose.plugins - LMS 1

We're quite far behind, let's start by just looking at the treadmill.

Upgrade Django to 1.11.15

Add credit pathway caching

Add user id to partner reports

Gate access to the CourseEnrollmentAdmin view with a waffle switch

Properly handle errors in award program certificates

LEARNER-6004

discussion component bokchoy tests

Exempt render_xblock from xfram options.

Update edx-drf-extensions version

Fix timezone issues in retirements_by_status_and_date

bok choy tests for course outline status section

Fix forums threads load issue in the user view.

TE-2524 Stop using nose.plugins in common/djangoapps and common/lib

Exempt render_xblock from xfram options otherwise, mobile apps, LTI
and other apps that iFrame our course-blocks won't work.

LEARNER-6002

Updated log to check which site cache are miss

LEARNER-5967

Management command: generate_jwt_signing_key

Allow site admins to disable integration for the Learner Records
feature in Credentials.

LEARNER-5987

Learn About Verified Certificates button on course outline page needs a focus indicator

Add created field to UserRetirementPartnerReportSerializer