Make it easier to test if the configure Travis Token is valid
@jorgeazevedo pointed out that https://github.com/guardian/support-frontend hasn't been kicking off it's post-deploy tasks for over a week - it took us a lot of digging to realise that someone had refreshed the Travis token at https://travis-ci.org/account/preferences and that we just needed to update PROUT_TRAVIS_TOKEN_OPENSOURCE in our Heroku settings - once that was done we merged a test PR and Prout successfully triggered a post-deploy-build.
Would be great if the diagnostics page at https://prout-bot.herokuapp.com/view/guardian/support-frontend could test the Travis credentials to see if they are still valid.
@johnduffell reported another occurrence of this issue - in this case, it seemed that Travis had forgotten that @prout-bot was a member of the @guardian GitHub organisation:

Hitting 'Revoke access' in GitHub for the Travis CI application...

...and logging out & in again to travis-ci.org got 'The Guardian' listed as an organisation:

...got us back to being able to make working Travis CI build requests:
body='{
"request": {
"branch":"master",
"config": {"script":"sbt ++$TRAVIS_SCALA_VERSION selenium:test || sbt ++$TRAVIS_SCALA_VERSION selenium:test"}
}}'
curl -v -s -X POST \
-H "Content-Type: application/json" \
-H "Accept: application/json" \
-H "Travis-API-Version: 3" \
-H "Authorization: token TOKEN-FROM-https://travis-ci.org/account/preferences-API-authentication" \
-d "$body" \
https://api.travis-ci.org/repo/guardian%2Fsupport-frontend/requests
No longer supporting Travis!