`locationType` hash or none during tests

When setting `locationType` to `none` or `hash` tests stops to work.
Specifically speaking the assets are not available. When trying to get any asset we receive:

```
Error: ENOENT, stat '/home/chrmod/Projects/test-project/tmp/class-tests_dist-Gw95HK2u.tmp/tests/assets/asset-name.css'
```

These seems to be correlated with missing BASE_TAG. 

This patch make sure that `test/index.html` will have a `<base href="/" />`. Will try to dig a little around, but currently that's the only way to have hash location in my app and working tests.