don't include chunkhashes in webpack test file names
don't include chunkhashes in webpack test file names

this will speed it up a tiny bit

test plan:
* webpack js tests should pass

Change-Id: I90b90efa340bc6b5738022c2706ae5887de4aeb3
Reviewed-on: https://gerrit.instructure.com/100645
Reviewed-by: Clay Diffrient <9dff2e5c98626d20d2848250c411e8009465bb87@instructure.com>
Product-Review: Ryan Shaw <ea3cd978650417470535f3a4725b6b5042a6ab59@instructure.com>
QA-Review: Ryan Shaw <ea3cd978650417470535f3a4725b6b5042a6ab59@instructure.com>
Tested-by: Jenkins

instructure/canvas-lms,instructure/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,SwinburneOnline/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,SwinburneOnline/canvas-lms,instructure/canvas-lms,SwinburneOnline/canvas-lms