modules next: remove module items

test plan:

1. click the cog
2. pick “remove”
   - it should fade out
   - it should not show up after refresh

Change-Id: Ib8c9beaf71665dd321efaea3a69069813ca96b1d
Reviewed-on: https://gerrit.instructure.com/38466
Reviewed-by: Jason Madsen <jmadsen@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Ryan Florence <ryanf@instructure.com>
QA-Review: Ryan Florence <ryanf@instructure.com>