BHV-12479: Fix SlideableSample, remove FlexLayout

Fixed a minor bug in SlideableSample and removed the never-
officially-released FlexLayout.

Enyo-DCO-1.1: Signed-Off-By: Gray Norton (gray.norton@lge.com)
Merge pull request #100 from enyojs/BHV-12479-graynorton

BHV-12479: Fix SlideableSample, remove FlexLayout

Reviewed-By: Cole Davis (cole.davis@lge.com)