Initial driver for HTU21DF

src/mgos_sht31.c

@@ -96,6 +96,7 @@ struct mgos_sht31 *mgos_sht31_create(struct mgos_i2c *i2c, uint8_t i2caddr) {
     return sensor;
   }
 
+  LOG(LL_ERROR, ("Failed to create SHT31 at I2C 0x%02x", i2caddr));
   free(sensor);
   return NULL;
 }