Quoting Whitespace Values

Trying to use this with Laravel (PHP) and getting

```
The environment file is invalid!
Failed to parse dotenv file. Encountered unexpected whitespace at [Site Name].
```

Even though I've wrapped it in
```
envkey_APP_NAME: "${{ vars.APP_NAME }}"
```

Would be great if there was an option to quote values containing whitespace, I see that's already supported for multi-line.