Merge pull request #126 from Edouard-chin/lazy-load-hooks

Use lazy-load hook:

Author: kaspth

lib/active_record/session_store.rb

@@ -108,11 +108,14 @@ def self.dump(value)
   end
 end
 
-require 'active_record/session_store/session'
+ActiveSupport.on_load(:active_record) do
+  require 'active_record/session_store/session'
+  ActionDispatch::Session::ActiveRecordStore.session_class = ActiveRecord::SessionStore::Session
+end
+
 require 'active_record/session_store/sql_bypass'
 require 'active_record/session_store/railtie' if defined?(Rails)
 
-ActionDispatch::Session::ActiveRecordStore.session_class = ActiveRecord::SessionStore::Session
 Logger.send :include, ActiveRecord::SessionStore::Extension::LoggerSilencer
 
 begin