accept multiple file paths from the command line

Change-Id: Ie857be359340494e7c327987fd9091b4d8a4fc99
Reviewed-on: https://gerrit.instructure.com/46232
Reviewed-by: Addison Higham <ahigham@instructure.com>
Product-Review: Michael Ziwisky <mziwisky@instructure.com>
QA-Review: Michael Ziwisky <mziwisky@instructure.com>
Tested-by: Michael Ziwisky <mziwisky@instructure.com>