Make basic auth exceptions an overridable list

Add API management settings.

Remove all mention of devpi, which we no longer use

Seems like we stopped using devpi with #971 two years ago.

Add dependency on "common" role to the elasticsearch role.

Update sandbox ami with new one built from scratch

Create Analytics Task Seed Job

Fixes broken sandbox builds

The downloads-distro.mongodb.org URL only has 2.6 packages?

Update mongo 3.0 play to use our two new roles

Use the newest version of the agents

Update nltk URLs

The old ones were returning 301s pointing to the updated URL

The role makes use of some variables from common_vars (notably COMMON_*_DIR), so
it should depend on the "common" role.  With this change applied, it's possible
to run the elasticsearch role using the run_role.yml playbook, which is
sometimes convenient.

This worked at one time, but stopped.  I've updated the URL to be
consistent with their current docs (and what we do in the mongo_3 role).

New payment processor configuration format

* defaults/main.yml: adds analytics schedule variables for configuring the AnalyticsSeedJob, with all analytics tasks enabled by default.
* templates/seed_job_template.xml: use updated analytics seed job config and description
* tasks/main.yml: generates a hashed password for the jenkins user, and adds jenkins-auth and create-seed-job tags.
* README.md: documents seed job parameters and jenkins auth change

Add playbook for managing edxapp users

Null API keys for Analytics AWS

ECOM-3940

Add show-repo-heads script for helping with diagnosis

Enable ecommerce on sandbox configuration conditionally.

Update wiki links in file headers

Add feature flag handle for ENABLE_MOBILE_REST_API

The headers were pointing to the old github wiki. Since we've officially
moved to Confluence, these links should be updated.