Improve e2e tests

[hansott]

• Use waitOn for speed (if server boots faster than 2000ms)
• Give entire error to t.fail(...) (more details)
• Sample apps that didn't respect passed port

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

:loudspeaker: Thoughts on this report? Let us know!