make 'development' features invisible in production

also remove the 'development' tag on existing features, other
than those that manually made themselves invisible in prod.
we'll let 'beta' suffice for the purpose of informing the user
that a feature is not fully baked.

test plan:
  - Deploy normally to your QA portal.  The 'quiz stats'
    feature flag should be available and operational.
  - Remove the testcluster.yml file from your config/
    directory (or move / back it up to a safe place)
  - Restart your QA portal.
  - The quiz stats feature flag should not be available
    or visible.

fixes CNVS-15724

Change-Id: I9e4e46f8cc4f54ac62f5226dbca09ae4885c93a9
Reviewed-on: https://gerrit.instructure.com/41551
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Josh Simpson <jsimpson@instructure.com>
QA-Review: Clare Strong <clare@instructure.com>
Product-Review: Cosme Salazar <cosme@instructure.com>