the Congress API docs use HTTPS

Author: konklone

docs/source/services/congress_deprecated.rst

@@ -6,5 +6,5 @@ sunlight.congress_deprecated
 
 The `Sunlight Labs Congress API
 <http://services.sunlightlabs.com/docs/Sunlight_Congress_API/>`_
-is deprecated in favor of the new `Sunlight Congress API <http://sunlightlabs.github.io/congress/migration.html>`_
+is deprecated in favor of the new `Sunlight Congress API <https://sunlightlabs.github.io/congress/migration.html>`_