update byebug

Change-Id: I556531bc8a959586161768a1fa8723b171bbedce
Reviewed-on: https://gerrit.instructure.com/36753
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Nick Cloward <ncloward@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>