Change close to minimize

Change-Id: I9eeb858b6d03a54114f332486ae0f60782912acf
diff --git a/dev/scss/main/buttongroup.scss b/dev/scss/main/buttongroup.scss
index 6a1ad38..8c3d620 100644
--- a/dev/scss/main/buttongroup.scss
+++ b/dev/scss/main/buttongroup.scss
@@ -71,6 +71,10 @@
 	      content: $fa-close;
       }
 
+      &.minimize::after {
+	      content: $fa-minimize;
+      }
+      
       &.plugin::after {
 	      content: $fa-plugin;        
       }