Change using of class object for custom translation model (#149)

Author: matko9

lib/i18n/backend/active_record/translation.rb

@@ -93,11 +93,11 @@ def lookup(keys, *separator)
           end
 
           def available_locales
-            Translation.select('DISTINCT locale').to_a.map { |t| t.locale.to_sym }
+            select('DISTINCT locale').to_a.map { |t| t.locale.to_sym }
           end
 
           def to_h
-            Translation.all.each.with_object({}) do |t, memo|
+            all.each.with_object({}) do |t, memo|
               locale_hash = (memo[t.locale.to_sym] ||= {})
               keys = t.key.split('.')
               keys.each.with_index.inject(locale_hash) do |iterator, (key_part, index)|