Batch Fetching Test is Flaky

[Adlai-Holler]

From #2899 http://jenkinsmaster-vpc-007.ec2.pin220.com/job/AsyncDisplayKit-PRs/1456/

ASCollectionViewTests
12:26:34 testThatWeBatchFetchUntilContentRequirementIsMet_Nonanimated, ((contentHeight) less than or equal to (requiredContentHeight + 2 * itemHeight)) failed: ("1074.5") is greater than ("1047") - Loaded too much content.

I will disable the test in that PR, and address this issue after that.

[Adlai-Holler]

This was addressed by #2935