Bug: Assign group within the db context manager

Assign the value to group within the db connection's context
manager. Initialise the group to an empty tuple at the very begining.

Fixes the error noted in
 https://github.com/genenetwork/gn-docs/blob/master/api/questions-to-ask-GN.md
and should now allow the curl invocation:

  curl -s https://genenetwork.org/api/v_pre1/group/BXD

to work as expected.

0 files changed, 0 insertions, 0 deletions