ESNext webpack via au build not using aurelia_project.environments file values

**I'm submitting a bug report**

au --version
1.0.0-beta.6

OS X 10.14.3

node -v
v10.14.0

npm -v
6.7.0

ESNext & Webpack

When I specify different values for baseUrl in my aurelia_project environment files they are NOT propagated into the .../dist/index.js file (via the index.ejs template)

When I add some commenting I can see that the aurelia environment files values have not been imported into the HtmlWebpackPlugin metadata area -- since they are referenced directly from the module export in webpack.config.js it seems too late to do anything about that...

How can I get the dist index.js to use values from the aurelia_project environment files ?

Start by reproducing the ESNext and Webpack build with `au build`, using different `baseUrl` values in the aurelia_project environment files. Read `webpack.config.js` and the `index.ejs` template, then trace how environment values reach the HtmlWebpackPlugin metadata and the generated `dist/index.js`. Done means the configured values are propagated into the generated output.

Written by the indexing model from the issue text.