Refer to this topic:
You could try using the version (commit ID) found either on github or in your development page source…
So viewing the source of this page currently:
<meta name="generator" content="Discourse 1.6.0.beta7 - https://github.com/discourse/discourse version b624c5cc9403d58d8d45125d7f70e60cddbb9ab9">
I can see the version is b624c5cc9403d58d8d45125d7f70e60cddbb9ab9
, this is the ID you could try using in place of tests-passed
on your staging / production.
To be clear - I’ve not tested using a commit ID - but it should work.