Revert "root file fix"

This reverts commit 23ab113.

Author: eisbilir

docker/Dockerfile

@@ -8,8 +8,6 @@ COPY . /challenge-api
 WORKDIR /challenge-api
 
 # Install the dependencies from package.json
-RUN mkdir -p /yarncache
-ENV YARN_CACHE_FOLDER=/yarncache
 RUN yarn install
 
-CMD yarn start
+CMD yarn start