0.4.0

• Integrated MQTT adapter (#165 )
• Support for storing messages in MongoDB (#237)
• Support for storing messages in InfluxDB (#236)
• Use UUID PKs with auto-incremented values (#269 )
• Replaced JWT with plain string tokens in things service (#268 )
• Emit non-SenML messages (#239 )
• Support for Grafana (#296)
• Added WS Load test (#299 )