adding admin subnet
Merge pull request #490 from edx/jarv/add-admin-subnet

adding admin subnet
using role dependencies for common/supervisor

Also renaming the deploy_* plays to the play name
using role dependencies for common and supervisor
supervisor depends on common
Don't do migrations.
Externalize migration settings.
Set scaling group limits to match desired capacity.
Fix json typos.
Merge pull request #494 from edx/feanil/stage

Feanil/stage
removing basic auth credentials.
Merge pull request #496 from edx/e0d/remove-basic

removing basic auth credentials.
Make basic_auth a global nginx parameter

Instead of enabling basic auth per role this makes it
an nginx parameter which makes more sense for sandboxes
and probably other servers where we want basic auth turned on
Merge pull request #497 from edx/jarv/better-basic-auth

Make basic_auth a global nginx parameter
adding option to enable basic auth when we provision
Merge pull request #498 from edx/jarv/basic-auth-provision

adding option to enable basic auth when we provision
add readme file for edx-west, prod-log playbook

While in here do a couple of cleanups:

- remove a log file
- add a simple playbook for refreshing roles on the prod log machine
fixing nginx_sites for provisioning
Merge pull request #504 from edx/jarv/fixing-provision

fixing nginx_sites for provisioning
adding vars_files for nginx