browser_ui/4_verify/cancelling_merge_request_in_merge_train_spec.rb | Verify Cancelling merge request in merge train when system cancels the merge request creates a TODO task

This is E2E scenarios for a new To-Do item in todos list when a MR in a Merge Train is canceled by system (see feature descriptions).

--Note: Each scenario should live in its own spec file within 4_verify section--

1. Log into GitLab as premium user
2. Create new project, setup runner, commit CI file and a text file using for this test
3. Create a new user
4. Enable Merge Train
5. Add user to project as Maintainer
6. Create a MR via API as this user (using his api token)
7. Login as this user and visit this merge request page
8. On this page wait for first pipeline to finish and click "Start merge trains" (or merge) button
9. Immediately create merge conflict by update the text file but push commit straight to master
10. On merge request page wait for system note "removed this merge request from the merge train"
11. Go to To-Dos page
12. Verify new item with content like Removed from Merge Train <MR ID> '[MR TITLE]' at [NAME SPACE] · [TIME AGO]

Old issue: #927 (closed)