#111 Add health-checks for UI, deep-thought, database and mosquitto

[TWilkin]

• Add health-check for UI by return 200 from /health if NGINX is up.
• Add health-check for deep-thought by adding HealthController which returns 200 if database (if enabled) and MQTT are accessible.
• Add health-check for database by initiating TCP connection to Postgres port.
• Add health-check for mosquitto by initiating TCP connection to MQTT port.
• Include updates for packages used by deep-thought.