Open collapse element does not close when calling $.collapse('show') on sibling

Created by: benjarwar

Given a Collapse Accordion, where only one item should be open at a time:

1. Click to open Item A
2. Use $.collapse('show') to open Item B, a sibling item in the same accordion
3. Note that both Items A and B are open

Expected behavior: Only Item B should be open.

To test: Using the Collapse Accordion example. Click the first item, then enter $('#collapseTwo').collapse('show') in your browser console.

Browser: Mac OSX Chrome 42.0.2311.90