Remove Atom feeds and old URLs in the form of GET /:username/updates/:id (#11247)

db/post_migrate/20190706233204_drop_stream_entries.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class DropStreamEntries < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def up
+    drop_table :stream_entries
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end