student context cards feature flag

closes FALCOR-10

Test plan:
  the account feature flags page should have a development feature flag for
  student context cards

Change-Id: Icc64642012e4cc94865093d9985e0d2a17c7fe42
Reviewed-on: https://gerrit.instructure.com/95369
Tested-by: Jenkins
Reviewed-by: John Corrigan <jcorrigan@instructure.com>
Product-Review: Simon Williams <simon@instructure.com>
QA-Review: Simon Williams <simon@instructure.com>

lib/feature.rb

@@ -504,6 +504,15 @@ END
       state: 'hidden',
       beta: true,
       development: true
+    },
+     'student_context_cards' =>
+    {
+      display_name: -> { I18n.t('Student Context Card') },
+      description: -> { I18n.t('Enable student context card links') },
+      applies_to: "RootAccount",
+      state: "hidden_in_prod",
+      beta: true,
+      development: true,
     }
   )