Publish refactoring (#298)

* 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

config_HCSR501.h

@@ -27,11 +27,14 @@
 /*----------------------------USER PARAMETERS-----------------------------*/
 /*-------------DEFINE YOUR MQTT PARAMETERS BELOW----------------*/
 #define subjectHCSR501toMQTT    Base_Topic Gateway_Name "/HCSR501toMQTT"
+
 #define TimeBeforeStartHCSR501 60000 //define the time necessary for HC SR501 init
 
 /*-------------------PIN DEFINITIONS----------------------*/
-#if defined(ESP8266) || defined(ESP32)
+#if defined(ESP8266) 
   #define HCSR501_PIN D5
+#elif defined(ESP32)
+  #define HCSR501_PIN 5
 #else
   #define HCSR501_PIN 7
 #endif