v0.1.6: Change default cron for check-in job

• Change default cron for check-in job so that it runs 1 hour before the messages-delivery job. This is to improve the precision (in days) of the delivery of messages
• Add troubleshooting information to README.md file

Pull this version by running docker pull jhonderson/gone-man-switch:v0.1.6, or use simply pull latest docker pull jhonderson/gone-man-switch:latest