specify DEFAULT_FILE_STORAGE in auth/env config

Add setting to update XBLOCK_SETTINGS

By deafult, nginx looks for ELB headers to forward

In the case of sandboxes, nginx listens on 443/80 and needs to pass
along the scheme of the request so that django knows if the client is
connecting over HTTP or HTTPS, rather than forwarding non-existant ELB
headers.

Update base edx image.

This one has a less full disk unlike the previous one that is full of assets.

Update the base installed AMI to only be 50GB instead of 100GB.

New base sandbox AMIs.

Add missing scripts to connect ro to prod dbs

Removing the unused/supported gerrit role

These vars are only used in the ad_hoc_reporting role, but their
prefix indicates that they're part of their services' roles.
This corrects the prefix.

Refactor to remove repeated tasks

Allow user to request Birch Vagrant box for VMware

Don't disable token checking on notes

The default is to enforce token checking (in edx-notes-api's common.py)
and we should be doing the same thing in deployed configuration.

Make this into a variable in case other systems (sandboxes?) want to
disable it in the future.

Remove reference to group_vars/all

elasticsearch monitor role

newrelic npi role

Create writable media dir on local filesystem (SOL-963)

Switch to using the vpc_class_b for these subnets

I suspect the third change is wrong - as is, it creates a route table,
but I cannot connect to the RDS.  However, there is no local gateway in
10.253.0.0 in loadtest, so the default isn't quite right either.

We should possible make SUBNET_[12]_CIDR easier to override, since I
ended up changing them anyway to use something other than .50.

E0d/service dbs

fix broken test

Provide separate internal/public API endpoints.

update github_post_status.py for jenkins_worker role

This allows us to route LMS requests over an internal ELB while public
JS direct requests to the API go over a separate ELB.