VerneMQ and Watson IoT should use matching MQTT topics

[johnwalicki]

The firmware subscribes to eight MQTT cmd topics that command the firmware to do a task.
The commands are described in https://github.com/openeew/openeew-firmware/blob/main/FIRMWARE.md

The firmware publishes acceleration event data to the MQTT broker on a status topic.

These MQTT topics follow a set of conventions defined by Watson IoT Platform.
Examples:

• iot-2/cmd/earthquake/fmt/json
• iot-2/evt/status/fmt/json

VerneMQ should match these MQTT topics.
This will make moving between MQTT brokers easier.

Before hacking the firmware, write test harness scripts using mosquitto_sub / mosquitto_pub CLI commands to prove that the VerneMQ MQTT broker be configured properly.

[andygrillo]

can we close this issue given that we are moving away from complicated MQTT systems ?