[Snyk] Upgrade ember-source from 3.19.0 to 3.28.6#19

snyk-bot wants to merge 1 commit intomasterhixio-mh/ember-cli-fastboot:masterfrom

snyk-upgrade-da08434d0106ffef0c3d28776609b90fhixio-mh/ember-cli-fastboot:snyk-upgrade-da08434d0106ffef0c3d28776609b90fCopy head branch name to clipboard