input-group btn border overlap when hovered

Created by: altechzilla

The .input-group-btn:last-child>.btn, .input-group-btn:last-child>.btn-group property should have z-index:2 to prevent a border overlapping issue on input-group when hovering.

Here is a demo video: https://www.dropbox.com/s/wq13tw1ttz9oah4/bootstrap_bug.mov?dl=0