Each time someone commits to Tracker, jenkins runs automatized test suite. However, there is no test making sure /users/ and /users/<username> at least loads.
You should write a test that tests /users/ and /users/<username> at least load correctly (ie. returns HTTP 200 Ok). You should include usernames with special characters Tracker supports in usernames.
Student is expected to send a patch for wikimedia-cz/tracker repository, hosted at Wikimedia Gerrit. When claiming task on GCI website, student should claim a respective Phabricator task as well.