Docker Build: ADD iens_scraper/ /app

When I run

`docker build --build-arg city=diemen -t iens_scraper .`

I receive an error

```
Step 9/19 : ADD iens_scraper/ /app
ADD failed: stat /var/lib/docker/tmp/docker-builder030593600/iens_scraper: no such file or directory
```

It looks like there is no directory such as iens_scraper in the project folder.

Should we update to `ADD scraper/ /app` ?