v2.10.0

New features:

• mqtt.publish_mode (always|on_change), allows to publish to MQTT every time a register data is read (#56, #32). Configurable per topic or globally on mqtt level.

Bugfixes:

• do not publish on topic if related modbus register data was changed in a way that generates the same mqtt payload (#38)
• fixed startup publish bug when the first received register value was compared to uninitialized variable
• fixed json generation for single element lists (#65)