Revert "Add google chrome and NPM modules to discourse_test image"

This reverts commit 050a1a6a83.

image/discourse_test/Dockerfile

@@ -15,13 +15,6 @@ RUN gem update bundler &&\
 
 RUN npm install -g eslint babel-eslint
 
-RUN wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add - &&\
-    echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list &&\
-    apt-get update &&\
-    apt-get install -y google-chrome-stable
-
-RUN sudo -E -u discourse -H npm install chrome-launcher chrome-remote-interface
-
 WORKDIR /var/www/discourse
 ENV LANG en_US.UTF-8
 ENTRYPOINT sudo -E -u discourse -H ruby script/docker_test.rb