naming fix: updateCart -> updateCartItem (#11)

Author: Egor Mesyats

package-lock.json

@@ -1,6 +1,6 @@
 export { default as home } from './home'
 export { default as addToCart } from './cart/addToCart'
-export { default as updateCart } from './cart/updateCartItem'
+export { default as updateCartItem } from './cart/updateCartItem'
 export { default as removeCartItem } from './cart/removeCartItem'
 export { default as cart } from './cart'
 export { default as fetchWithGraphQl } from './fetchWithGraphQl'