use django-tables2 v2 alpha

requirements.txt

@@ -14,8 +14,8 @@ gitdb2==2.0.3             # via gitpython
 gitpython==2.1.9
 idna==2.6                 # via requests
 ndh==3.5.1
-pytz==2018.3              # via django
+pytz==2018.4              # via django
 requests==2.18.4
 smmap2==2.0.3             # via gitdb2
 urllib3==1.22             # via requests
-https://github.com/jieter/django-tables2/archive/two.zip
+https://github.com/jieter/django-tables2/archive/master.zip