add open-ended-message to XQUEUE_QUEUES

due to https://github.com/edx/edx-platform/blob/master/common/lib/xmodule/xmodule/open_ended_grading_classes/openendedchild.py#L79

I added  open-ended-message to XQUEUE_QUEUES
git checkouts over ssh need ~/.ssh to exist
pip installs are hanging for xqueue

We were hanging on this:

```
Obtaining pika from
git+https://github.com/pika/pika.git@a731347fc0#egg=pika (from -r
/edx/app/xqueue/xqueue/requirements.txt (line 14))
  git clone in /edx/app/xqueue/venvs/xqueue/src/pika exists with URL
git://github.com/pika/pika.git
  The plan is to install the git repository
https://github.com/pika/pika.git
What to do?  (s)witch, (i)gnore, (w)ipe, (b)ackup
```
Merge pull request #1549 from edx/jarv/exists-actions-w-for-xqueue

pip installs are hanging for xqueue
TRACKING_SEGMENTIO_WEBHOOK_SECRET
TRACKING_SEGMENTIO_WEBHOOK_SECRET defaults
Merge pull request #1550 from edx/han/TRACKING_SEGEMENTIO

TRACKING_SEGMENTIO_WEBHOOK_SECRET
Adding new env config value
Merge pull request #1551 from edx/e0d/oauth2

Adding new env config value
Moving to lms.auth
Merge pull request #1552 from edx/han/webhook

Moving to lms.auth
adding server-status pages
changelog update for new nginx server files
wording change
using a more generic image
Merge pull request #1553 from edx/jarv/server-status

adding server-status pages
separate var for image to make overrides easier
Merge pull request #1554 from edx/jarv/server-status

separate var for image to make overrides easier
initial working version
var fix.