Returns list of all groups that the current_user belongs to

GET https://secure.splitwise.com/api/v3.0/get_groups

Parameters:

1. none

Return value (Detailed info for all groups that include the authenticated user):

1. id
2. name
3. group_type
4. country_code
5. updated_at
6. members
   1. standard User hash for each member + one additional field:
   2. balance
7. suggested_repayments
   1. from
   2. to
   3. amount