Manage Group Memberships via REST API

Hello,

  At the moment I don't see a way to do this, but I just wanted to make
sure I wasn't missing anything.

  When we terminate employees that had access to RT, we put them into a
group called Terminated Employees. Being a member of this group will
re-assign any tickets they owned, on reply, back to nobody.

  I would like to be able to add the user to this group when our
termination script runs, but I don't see any way to do that. Can anyone
confirm if there is a way to modify group memberships via the REST API?
Currently running 4.2, but upgrading to 4.4 soon.

Thanks
-Matt