converts facebook/index js_block into js_bundle

test plan:
* regression test facebook index

Change-Id: Ieba5b1d96598b8b08ef8d5073f124d10b654d9c3
Reviewed-on: https://gerrit.instructure.com/29150
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Stanley Stuart <stanley@instructure.com>
QA-Review: Matt Fairbourn <mfairbourn@instructure.com>
Product-Review: Landon Wilkins <lwilkins@instructure.com>