Feature/add shtc3 (#843)

* Add SHTC3

* remove adc config

platformio.ini

@@ -113,6 +113,7 @@ m5stickcp = https://github.com/m5stack/M5StickC-Plus.git
 m5stack = M5Stack@0.3.0
 smartrc-cc1101-driver-lib = SmartRC-CC1101-Driver-Lib@2.3.5
 stl = https://github.com/mike-matera/ArduinoSTL.git#7411816
+shtc3 = https://github.com/sparkfun/SparkFun_SHTC3_Arduino_Library
 somfy_remote=Somfy_Remote_Lib@0.2.0 
 
 [env]
@@ -205,6 +206,7 @@ lib_deps =
   ${libraries.onewire}
   ${libraries.dallastemperature}
   ${libraries.rfWeatherStation}
+  ${libraries.shtc3}
 build_flags =
   ${com-esp.build_flags}
   '-DZgatewayRF="RF"'