try to enable composer

Dockerfile

@@ -3,6 +3,6 @@ ENV TZ=Europe/Berlin
 COPY . .
 ONBUILD COPY composer.* ./
 USER root
-#RUN composer install --no-dev --no-interaction --prefer-dist --optimize-autoloader --ignore-platform-reqs
+RUN composer install --no-interaction --optimize-autoloader
 RUN chown -R nobody:nobody /var/www/html
 USER nobody