Add ability to specify range with --until, or grouping with --group

[andy-novikov]

I would like to slice stats for an organisation on a timely basis.
We have 2w sprints and I'd like to see how the organisation performed during each of those sprints.

Currently org-stats only allows gathering all data since a starting point in time.

Possible solutions:

• --until that accepts duration in same format as since and used to format a query in form created:2017-01-01..2018-01-01
• --group that accepts duration and is used to generate queries and outputs accordingly. This would generate multiple outputs.

Note:
created: filter accepts range in format created:2017-01-01..2018-01-01

[caarlos0]

nice idea! :)

[mrusme]

I wanted to request this feature as well, it would be super useful for period-based stats!

[dvdplm]

+1 for this