Fix BMI calculation to round to 1 decimal place

Author: cywong-dev

Sprint-2/3-mandatory-implement/1-bmi.js

@@ -16,4 +16,5 @@
 
 function calculateBMI(weight, height) {
     // return the BMI of someone based off their weight and height
-}
+    return Math.round((weight/(height*height)*10))/10;
+}