* factoring of the publishing function
* integration of json publishing to MQTT
* receiving and transcode json messages from mqtt
* replace the TRACE runtime condition by a buildtime one so as to decrease program size
* remove retainFlag parameter not necessary for the moment
* Increase the scope of tests for arduino mega and esp32
* Update arduinojson library to 5.13.3
* add macros to choose between simple or json publishing or both
* differentiate build test for ATmega2560
* correct wrong sprintf definition
* change IDE version for continuous integration
* let default warning level in arduino ide
* correct pins for ESP32
* reorganize user_config
* some minor correction after coadcy checks
* Put serial communication speed as a parameter in user_config.h
* complete gateway file
receiving ok
sending ko
#32
* add rfm69 to CI
* change receiver key and minor improvments
#32
now ok on receiving and sending with RFM69
* add schema and tested pinout for RFM69/RF/IR wiring
#32
* RFM69 library add
* Implement newremoteswitchlibrary for KlikAanKlikUit / ClickOnClickOff protocol
#3
* add dependency for CI and link to the library
* compilation error for arduino correction
* Sketch size decrease
* remove nano from CI
* Divide user_config into one file per gateway/sensor for lisibility
Florian