Rebuilds Don't Seem To Invalidate

[chadhietala]

Steps to repro:

1. git clone git@github.com:sass-eyeglass/ember-cli-eyeglass.git
2. cd ember-cli-eyeglass && yarn
3. ember s
4. Change color from yellow to blue in tests/dummy/lib/eager/addon/styles/addon.scss
5. Notice that styles do not update

I also confirmed that the templates do update and appears to only be the styles.

[stefanpenner]

Thanks for the reproduction, I was able to immediately confirm the issue.