________  _________  ___       ________  ________      
|\   __  \|\___   ___\\  \     |\   __  \|\   ____\     
\ \  \|\  \|___ \  \_\ \  \    \ \  \|\  \ \  \___|_    
 \ \   __  \   \ \  \ \ \  \    \ \   __  \ \_____  \   
  \ \  \ \  \   \ \  \ \ \  \____\ \  \ \  \|____|\  \  
   \ \__\ \__\   \ \__\ \ \_______\ \__\ \__\____\_\  \ 
    \|__|\|__|    \|__|  \|_______|\|__|\|__|\_________\
                                            \|_________|

                                            
This test will involve working with simulated data for community
health organizations (CHOs). CHOs are generally structured with a
geographic hierarchy, so that e.g. a regional health facility may be
responsible for managing a number of health posts located at sites
within its region etc.  An enduser of our platform may have data
access to more than one CHO.

Portions of this challenge should be accomplished in SQL, but most of
the challenge should be done in JavaScript.
                                            
Stage 1:
We have schemas for a fixtures table and a user organizations table
(see table-schemas.sql).
Write (but do not attempt to run) SQL queries that will produce
a list of the fixtures for a given organization name, a list of
orgs for a given user name, and a list of fixtures for a given user name.

Stage 2:
We also have a JSON file which contains fixtures data (fixtures.json);
this is keyed by organization id. You will note that fixtures have a
"parent_id" field; when this is not null it corresponds to a 
"higher-level" fixture. Each organization should have exactly one 
fixture with a null parent_id. Write a function which will return a 
tree structure of fixtures given an organization id.  Each node of the 
tree should contain all of the information associated with the fixture
(aside from the organization).

Stage 3:
We have a JSON file which contains user data (users.json), and a second
file which contains user organization data (user_organizations.json).
Write a function which takes a username, retrieves the fixture trees for
all organizations the user has access to, and then merges the trees under
a joint root node.  Ensure that the top node of each of the subtrees 
identifies which organization it comes from.
This should use the solution to Stage 2.

Bonus Stage:
Write a "validation" SQL query (using PostGIS) which identifies when
a fixture does not lie within the boundary of the parent fixture.

Bonus Bonus Stage:
Write unit tests for Stages 2 and 3, using the Jest unit testing framework.