Allow groups to be exported

[jathak]

61A Su18 is using the groups feature of Ok to allow students to select their exam group. To export the selected groups (for use in assigning seating areas outside of Ok), I'm just connecting to the staging environment manually and writing Python to grab groups from the database.

It would be nice to allow exporting groups to allow this sort of use case (exporting groups without associated submissions) for others in the future.

[colinschoen]

Can you include the query or output format that would be must useful