Coverage in Engines  #180

I'm having trouble getting coverage in engines to work. This is specific to a private repo, but I've tried running coverage in this repo without success.

Steps to reproduce:

cd test/fixtures/my-app-with-in-repo-engine/
COVERAGE=true ember test
cd ../../..
vim coverage/coverage-summary.json 

This will show that there are a total of 0 lines in the report although all of the tests have been run.

There is an active PR that seems related to this:

• Add template instrumentation. #103

Some past issues that seem related:

• Support in-repo engine coverage #86 this asked to allow for coverage of in-repo addons. This led to the above test that did not show coverage of lines in the in-repo addon

As a followup for my specific scenario: my app/ folder and /lib folder (lib contains all my engines) are on the same level. When I move the lib folder into the app folder, coverage works fine