adjusted the library to give chance to user to be bale to select the i2c pins

src/I2CMotor.h

@@ -6,7 +6,7 @@
 
 class I2CMotor {
 public:
-    I2CMotor(uint8_t sda = 8, uint8_t scl = 9, uint32_t freq = 100000);
+    I2CMotor(uint8_t sda = 8, uint8_t scl = 3, uint32_t freq = 100000);
 
     void begin();
     bool found();