Chrome (v58+) often gets disconnected during unit tests (causing them to fail).
This has been happening locally (on Windows) and on Travis. The exact reasons
are not known, but it seems that some of the `AppComponent` tests are to blame.
Based on the discussion in https://github.com/jasmine/jasmine/issues/1327 (and
plenty of trial-and-error), using Jasmine's `done()` callback before each of
test (even calling it synchronously) fixes the issue.