Reduce margin between modal footer buttons

Set margin to 0 except left margin on any button after another button
Now matches the 8px from the design spec

app/assets/stylesheets/framework/modal.scss

@@ -53,6 +53,10 @@
   display: flex;
   flex-direction: row;
+  .btn {
+    margin: 0;
+  }
+
   .btn + .btn:not(.dropdown-toggle-split),
   .btn + .btn-group,
   .btn-group + .btn {