Update Django and Wagtail to latest release

requirements/base.txt

@@ -1,8 +1,8 @@
-Django==1.11.2
+Django==1.11.3
 django-dotenv==1.4.1
 # http://docs.wagtail.io/en/v1.8.1/topics/search/backends.html#elasticsearch-backend
 # Not utilized by default; uncomment and review the above document if you require elasticsearch
 # elasticsearch==5.1.0
-wagtail==1.10.1
+wagtail==1.11
 wagtailfontawesome==1.0.6
 Pillow==4.0.0