Upgrade django-babel-underscore and markey

requirements/edx/base.txt

@@ -14,8 +14,8 @@ cryptography==1.3.1
 cssselect==0.9.1
 dealer==2.0.4
 defusedxml==0.4.1
-django-babel-underscore==0.4.2
-markey==0.7  # From django-babel-underscore
+django-babel-underscore==0.5.1
+markey==0.8  # From django-babel-underscore
 django-celery==3.1.16
 django-config-models==0.1.3
 django-countries==4.0