FEATURE: allow "developer" account flagging via developers table

This mechanism for flagging developer accounts will eventually replace
DISCOURSE_DEVELOPER_EMAILS

app/models/developer.rb

@@ -0,0 +1,22 @@
+require_dependency 'distributed_cache'
+
+class Developer < ActiveRecord::Base
+  belongs_to :user
+
+  after_save :rebuild_cache
+  after_destroy :rebuild_cache
+
+  @id_cache = DistributedCache.new('developer_ids')
+
+  def self.user_ids
+    @id_cache["ids"] ||= rebuild_cache
+  end
+
+  def self.rebuild_cache
+    @id_cache["ids"] = Set.new(Developer.pluck(:user_id))
+  end
+
+  def rebuild_cache
+    Developer.rebuild_cache
+  end
+end