Add missing translation tokens

Author: cuducos

simple_history/models.py

@@ -12,7 +12,7 @@
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.encoding import smart_text
 from django.utils.timezone import now
-from django.utils.translation import string_concat
+from django.utils.translation import string_concat, ugettext as _
 
 try:
     from django.apps import apps
@@ -206,9 +206,9 @@ def get_instance(self):
                 user_model, null=True, related_name=self.user_related_name,
                 on_delete=models.SET_NULL),
             'history_type': models.CharField(max_length=1, choices=(
-                ('+', 'Created'),
-                ('~', 'Changed'),
-                ('-', 'Deleted'),
+                ('+', _('Created')),
+                ('~', _('Changed')),
+                ('-', _('Deleted')),
             )),
             'history_object': HistoricalObjectDescriptor(model),
             'instance': property(get_instance),

simple_history/templates/simple_history/object_history.html

@@ -35,7 +35,7 @@
                       {{ action.history_user }}
                     {% endif %}
                   {% else %}
-                    None
+                  {% trans "None" %}
                   {% endif %}
                 </td>
               </tr>