I'm having a nightmare with using environment variables in my SPFx project. I have:

- a .env in the root of my project
- variables within this file all starting with REACT_APP_
- references to these variables using process.env.REACT_APP_
- restarted gulp, cleaned and built many times
- installed dotenv-webpack
- installed dotenv
- added 'node' to the types in tsconfig.json
- confirmed I can read process.env.NODE_ENV

Any variables inside my .env file just appear as 'undefined' when I try reading them and view with console.log.  Is there something I am missing?  I thought this was an easy thing to set up.

.env:
```
REACT_APP_TEMPLATE_LIST='text'
```
WebPart.ts:
```
console.log(process.env.REACT_APP_TEMPLATE_LIST)
```
This reads as undefined.

Please help!