add missing gettext import

welco/views.py

@@ -29,6 +29,7 @@ from django.shortcuts import resolve_url
 from django import template
 from django.template import RequestContext
 from django.utils.encoding import force_text
+from django.utils.translation import ugettext_lazy as _
 from django.views.decorators.csrf import csrf_exempt
 from django.views.generic import TemplateView