omit the border of scroll-top-button

Author: kazuhitonakayama

stylesheets/scroll-button.scss

@@ -20,6 +20,7 @@ button.arrow-for-scrolling-top {
     -o-border-radius: 50%;
     &.show {
         opacity: 1;
+        border: none;
         transition: 1s;
         -webkit-transition: 1s;
         -moz-transition: 1s;