message: add JAVA_OPTS to Dockerfile
  fix
diff: FROM openjdk:8-jre-alpine
  ENV SPRING_OUTPUT_ANSI_ENABLED=ALWAYS \
  + JAVA_OPTS="" \
  JHIPSTER_SLEEP=0
  # add directly the war
  @@ -10,4 +11,4 @@ VOLUME /tmp
  EXPOSE 8761
  CMD echo "The application will start in ${JHIPSTER_SLEEP}s..." && \
  sleep ${JHIPSTER_SLEEP} && \
  - java -Djava.security.egd=file:/dev/./urandom -jar /app.war
  + java ${JAVA_OPTS} -Djava.security.egd=file:/dev/./urandom -jar /app.jar
  