Needed for edge which doesn't have a prod_grader db

There is some work outstanding before this is ready but I believe
it's complete enough to merge.  There will be more logic added
to sanitize and change the db password after the clone is complete

This PR makes the following changes:

* Defaults to the edx.org zone instead of a vpc zone
* Takes an AWS id and secret to query another account for instance info
* Adds some safe guards around duplicate dns entries
* Creates an ban list for elbs

Always write the supervisor files and link them as necessary.

Drop the configs in the supervisor available directory. Instead of having a
seperate cfg dir for each service.

Seperate devstack logic from disabling supervisor tasks. Add the new flag so
devstack continues to not startup supervisor. Use new supervisor_available_dir
everywhere.

Remove mongo logic from abbey and remove stage_release. This should completely
remove our tie ins to mongo.

Also removing monitor repos script which depended on stage_release. We can add
in similar logic when we're ready to automate building the AMIs on rc branch
creation.

Updated requirements.