Fix for properly work with defined 'list_filter' option
Merge pull request #6 from 612d7368/fix-list_filter

Fix for properly work with defined 'list_filter' option
Make order field a database index.
Use aggregate Max to fetch new order value.
Merge pull request #7 from fladi/aggregate

Make "order" field an index and use Max aggregate to find next order value.
Add latest Django versions to Travis
Create CHANGES.md
Bump version to 0.3.0
Add Django 1.6 and remove Django 1.3 from travis