Error: error parsing config file: error unmarshalling config: yaml: unmarshal errors: line 18: field user not found in type v2.MetadataTest

I'm exploring this tool and wrote a super basic [`config.yml`](https://github.com/edouard-lopez/explore-container-testing/commit/0555855973e62c36339e940a20b049e90477734c):

schemaVersion: 2.0.0
fileExistenceTests:
- name: 'Pure Test directory exists'
path: '/tmp/.pure/'
shouldExist: true
permissions: 'drwxr-xr-x'
uid: 1000
gid: 1000
isExecutableBy: 'group'

metadataTest:
user: "luke"

## Error

❯ container-structure-test test \
--image pure \
--config config.yml

===================================
====== Test file: config.yml ======
===================================
=== RUN:
--- FAIL
duration: 0s
Error: error parsing config file: error unmarshalling config: yaml: unmarshal errors:
line 12: field user not found in type v2.MetadataTest

===================================
============= RESULTS =============
===================================
Passes: 0
Failures: 1
Duration: 0s
Total tests: 1

FAIL
FATA[0000] FAIL
make: *** [makefile:2: test] Error 1

## Question

What's the matter with my test?

Update: link to [reproducible repo](https://github.com/edouard-lopez/explore-container-testing/commit/0555855973e62c36339e940a20b049e90477734c)