Running schema.sql errors out with missing UUID extension

I used the instructions on the Citus website, and started up a cluster using the CloudFormation template. When I try to create the schema.sql, I get an error message saying that the UUID extension is missing:

postgres=# \i schema.sql

psql:schema.sql:8: ERROR:  function uuid_generate_v4() does not exist

HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

psql:schema.sql:18: ERROR:  function uuid_generate_v4() does not exist

HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

psql:schema.sql:20: ERROR:  relation "stores" does not exist

LINE 1: SELECT create_distributed_table('stores', 'store_id');

                                        ^

Citus' sequence support improved in the past two releases. Could we use sequences in this example? If not, could we include the UUID extension as part of the CloudFormation template?