Data-Attribute in Event Manage Widget

I’m trying to use the http://www.addthis.com functionality within the Event Manager widget, and it seems to strip out any data-attribute items. For example if I use the follow code, it’s stripped out of the template:

<li data-url="http://www.google.com">Test</li>

Any ideas on how to solve this?

https://wordpress.org/plugins/events-manager/