FEATURE: better email in support

FEATURE: new incoming_email model
FEATURE: infinite scrolling in emails admin
FEATURE: new 'emails:import' rake task

db/migrate/20151109124147_drop_group_managers.rb

@@ -10,6 +10,6 @@ class DropGroupManagers < ActiveRecord::Migration
   end
 
   def down
-    raise ActiveRecord::IrriversableMigration
+    raise ActiveRecord::IrreversibleMigration
   end
 end