ConfigurableProduct module fixes

- Fix code style errors

Author: arendarenko

app/code/Magento/ConfigurableProduct/view/frontend/web/js/configurable.js

@@ -392,8 +392,9 @@ define([
                         }
                     } else {
                         allowedProducts = options[i].products.slice(0);
-                        if (typeof allowedProducts[0] !== "undefined"
-                            && typeof optionPrices[allowedProducts[0]] !== "undefined") {
+
+                        if (typeof allowedProducts[0] !== 'undefined'
+                            && typeof optionPrices[allowedProducts[0]] !== 'undefined') {
 
                             optionFinalPrice = parseFloat(optionPrices[allowedProducts[0]].finalPrice.amount);
                             optionPriceDiff = optionFinalPrice - basePrice;