Merge branch '104-update-backend-timezone' into 'master'

Resolve "Update backend timezone"

Closes #104

See merge request marcel.schwarz/2020ss-qbc-geofence-timetracking!79

backend/Dockerfile

@@ -5,6 +5,7 @@ RUN ["gradle", "bootJar"]
 
 FROM openjdk:11-jre-slim
 WORKDIR /root
+ENV TZ=Europe/Berlin
 COPY --from=build /root/build/libs/*.jar app.jar
 EXPOSE 5000
 ENTRYPOINT ["java", "-jar", "app.jar"]