Update Dockerfile, added the export NODE_OPTIONS command as workaround for issue #41

Dockerfile

@@ -14,6 +14,7 @@ FROM node AS node
 
 COPY . /var/www/html
 WORKDIR /var/www/html
+RUN export NODE_OPTIONS=--openssl-legacy-provider
 RUN npm --version && npm install && npm run prod
 
 #### Step 3 : the actual docker image