Integration test running with test server

README.md

@@ -18,6 +18,10 @@ You need chrome and chromedriver installed. The Dockerfile builds an image that
 
 TODO add firefox and geckodriver
 
+The container can access the outside without setting a port or a network. The network or port is only necessary when wanting to connect the host machine to the docker container. You can run a test that spawns a test server and uses the webdriver to load the page like this:
+
+    docker run --rm -it -v $PWD:/usr/src/app btroops npm run test:integ
+
 ## Rough way to save the SVG map generated by JavaScript client-side
 
     const XMLS = new XMLSerializer();