background: should get the correct response failed

[flaky-bot]

Note: #491 was also for this test, but it was closed more than 10 days ago. So, I didn't mark it flaky.

---

commit: fae958d
buildURL: Build Status, Sponge
status: failed

Test output

The expression evaluated to a falsy value:
assert.ok(res.includes('how are you'))
  + expected - actual

  -false
  +true

AssertionError [ERR_ASSERTION]: The expression evaluated to a falsy value:
assert.ok(res.includes('how are you'))
at Context.<anonymous> (test/app.test.js:124:12)
at process._tickCallback (internal/process/next_tick.js:68:7)</pre></details>

[flaky-bot]

Looks like this issue is flaky. 😟

I'm going to leave this open and stop commenting.

A human should fix and close this.

---

When run at the same commit (fae958d), this test passed in one build (Build Status, Sponge) and failed in another build (Build Status, Sponge).