Integration test stability: add delay before starting TimersTest

[douglowder]

• Motivation

Locally I'm seeing consistent failures in IntegrationTests/TimersTest.js. Adding a little delay before starting the first test seems to make these issues go away.

[facebook-github-bot]

By analyzing the blame information on this pull request, we identified @sebmarkbage to be a potential reviewer.

[douglowder]

@bestander here's another change that I think might improve test stability....

[bestander]

@facebook-github-bot shipit

[facebook-github-bot]

@bestander has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[bestander]

Thanks, @dlowder-salesforce.
This merged on master branch, let's see if it improves stability.

I looked at the last 10 build failures on Master branch https://travis-ci.org/facebook/react-native/builds/170729100
6 out of 10 were caused by the objc-tvos.
Do you have an idea why it seems less stable than objc-ios?

[douglowder]

@bestander Looks like there are intermittent failures with testLogging and testPropertiesUpdateTest. The latter happens when the simulator won't come up sometimes, and can also happen in objc-test-ios. The logging test failures seem to be cases where the message text doesn't match expected values when running the tvOS tests. It's a bit strange -- I would expect those failures to happen every time, or not at all. I'll take a look.

[douglowder]

Interesting.... If I restart the packager and remove UIExplorer app from the tvOS simulator, it seems to fail every time, but not always at the same line. Bizarre. It succeeds after that.

[douglowder]

@bestander Found the issue. On tvOS, logging messages (due to missing components that don't exist in tvOS) are arriving at the same time as the test log messages, causing intermittent test failures. Submitting a PR to fix this.