set button images to aria-hidden

src/components/close-button/close-button.jsx

@@ -20,6 +20,7 @@ const CloseButton = props => (
         <img
             className={styles.closeIcon}
             src={closeIcon}
+            aria-hidden="true"
         />
     </div>
 );

src/components/icon-button/icon-button.jsx

@@ -16,6 +16,7 @@ const IconButton = ({
         <img
             className={styles.icon}
             src={img}
+            aria-hidden="true"
         />
         <div className={styles.title}>
             {title}