chore(package): update ember-cli to version 3.1.2
chore(package): update ember-cli to version 3.1.2

Closes #3664
thecoolestguy/frontend,djvoa12/frontend,djvoa12/frontend,dartajax/frontend,ilios/frontend,dartajax/frontend,jrjohnson/frontend,thecoolestguy/frontend,ilios/frontend,jrjohnson/frontend