Prod bundle contains compiler after AoT

**I'm submitting a ...**
```
[x] bug report => search github for a similar issue or PR before submitting
[ ] feature request
[ ] support request => Please do not submit support request here, instead see use [gitter](https://gitter.im/mgechev/angular2-seed) or [stackoverflow](https://stackoverflow.com/questions/tagged/angular2)
```

**Current behavior**

```sh
git clone --depth 1 git@github.com:mgechev/angular-seed.git
...
npm i
npm run sme.prod
```
then i get an html report

**Expected behavior**

With AoT the bundle shouldn't contain a compiler.

**Please tell us about your environment:**

Mac OS

* **Angular Seed Version:** `ca6405ea27ec5f08f02e84e11837bdd465033613`

* **Node:** `node --version` = 9.11.0

Start by reproducing the report with npm i and npm run sme.prod from the specified Angular Seed revision. Inspect the production build path and generated HTML report to determine why the AoT bundle includes the compiler. Done means the production bundle no longer contains the compiler while the production build still succeeds.

Written by the indexing model from the issue text.