NOTE: This is supposed to say "Build Error", because that's what it demonstrates.
If you do not already have an account on Tenon.io, you need one to use this. Head over to https://tenon.io/register.php.
Once you're registered and confirmed, get your API key at https://tenon.io/user/apikey.php
This is a demonstration of using Tenon as a Grunt task. It uses the grunt-tenon-client to test a folder of HTML files using Tenon API and using Tenon in a watch task. It also demonstrates using grunt-githooks to run the tenon task on commit.
It also demonstrates using Tenon in a Continuous Integration Scenario, using Travis (view sample output at: https://travis-ci.org/tenon-io/grunt-tenon-demo/). Note: When viewing the Travis-CI output, the build fails because that's exactly what you want in this case. The Grunt Tenon task is specifically designed to exit if errors are found.
Take a bit of time to explore the Gruntfile and .tenonrc file to see how the options can be used for your purposes.
Don't forget to also Read The Fine Manual for the full range of API parameters!