Make collapse transition duration dynamic
Created by: artifex404
Collapse.js transition duration is taken from a constant of value of 600.
However in some cases the transition needs to be altered with CSS, for example:
.collapsing {
transition: none;
}
This prevents the collapsing trigger to work properly as it always waits for the 600ms timeout.
The collapse.js transition duration should take its value dynamically from css.
Demo: https://codepen.io/artifex404/pen/LewydR (Note: auto updating is disabled, rerun codepen to see changes)