Use bool instead of boolean in examples

In the Arduino IDE, boolean is an alias for bool.
The Arduino IDE might deprecate boolean in the future, see
https://github.com/arduino/Arduino/issues/4673 for details.

examples/MotionSensor/MotionSensor.ino

@@ -60,7 +60,7 @@ void presentation()  {
 void loop()     
 {     
   // Read digital motion value
-  boolean tripped = digitalRead(DIGITAL_INPUT_SENSOR) == HIGH; 
+  bool tripped = digitalRead(DIGITAL_INPUT_SENSOR) == HIGH;
         
   Serial.println(tripped);
   send(msg.set(tripped?"1":"0"));  // Send tripped value to gw