Make buttongroup available in plugins

Change-Id: I4226039a3511963881c76d059de4b652290949ec
diff --git a/dev/scss/base/base.scss b/dev/scss/base/base.scss
index d5cb6c8..4f4c77e 100644
--- a/dev/scss/base/base.scss
+++ b/dev/scss/base/base.scss
@@ -10,6 +10,7 @@
 @import "banner";
 @import "showPWD";
 @import "copyToClipboard";
+@import "buttongroup";
 
 /**
  * Basic global CSS rules for Kalamar