Merge branch 'release/v0.6.0'
Add other aggregates options. (Sum, Avg, StdDev, Max, Min, Variance)
Merge pull request #19 from hbkfabio/master

Add other aggregates options. (Sum, Avg, StdDev, Max, Min, Variance)
Merge branch 'master' into develop
Merge branch 'develop' of github.com:Star2Billing/django-admin-tools-stats into develop