Settings for S3-backed Course Block Structures

Fix devstack issues DEVSTACK-28 and DEVSTACK-29

Remove compile translations step in insights role

TNL-6611

We keep the compiled translation files in git already and have an automated job that compiles them regularly, so there's no need to keep this step that seems to be causing the insights AMI building to fail.

script to shovel between rabbitmq clusters

Add course catalog visibility feature

Add support for HLS-related codecs.

Docker image name problem in compose file.

Add a playbook for installing and configuring Graphite.

This playbook will install carbon-cache and graphite-api to provide a
minimalistic starting point for metrics collection.

It currently installs all components from their upstream source (albeit
with defaults that point to tags, and not master/development branches).
It uses systemd, and so is tailored specifically to Ubuntu 16.04.

It currently does not support any of the advanced configuration such as
multiple carbon-cache process + carbon-relay.  It is also lacking many
variables to fully tweak the various configuration files, although
there's support for fully configuring the storage schemas.

There is a small "master" playbook -- edx-monitoring -- for running the
role, and in the future, supporting the culmination of other playbooks
to build out an all-in-one monitoring server: Graphite, Grafana, etc.

Update to the latest awscli.

Add an ec2 related plugin

This avoids running the entire role if you just want one new plugin.
It intentionally makes you restart Jenkins so you can put it in quiet
mode, wait out any jobs and then restart.

Also address prior nit regarding grouping plugins by usage

Prompted because the awscli on go-agents needs to be above 1.10.47 to be
able to take advantage of IAM roles for tasks automatically.

Explicitly allow read access to gocd log directory.

We now make use of the management command's initial-only flag silently exit if the countries table is already populated.

ECOM-7422

We don't use this bot.

updated migration rollback docs

edxops/forum not found: does not exist or no pull access

Switch from git_add_course to standard import

Adds ANALYTICS_API_AGGREGATE_PAGE_SIZE, default value 10

git_add_course uses the platform's sysadmin dashboard which assumes it
can create an xlog mongo database and write into it without auth
configured.  This is not something we want to spend more time enabling,
so switch to our 'standard' import technique.

This relies on the demo role more than I would like, but we have a
backlog task to clean that role up, and can touch this at the same time
(this role has always imported a bunch of vars from demo, so I'm not
 adding any new deps).

Allow for a list of users that have credentials.

Added monitoring tag to rabbitmq ansible

and CHANGELOG entry.