Issue title: mouseover
 Issue body: The [`mouseover`](https://developer.mozilla.org/en-US/docs/Web/Events/mouseover) event is not part of the library. It'll be great if you added it.
 Comments: 
 Comment 0: Are there any browsers that don't support this?
 Comment 1: Well I wasn't sure of that for a problem I was trying to fix. But thankfully it's all resolved now and wasn't anything to do with the `mouseover`. 

It seems `mouseover` has strong browser support so feel free to leave this out. 
 Comment 2: Available at https://caniuse.com/#feat=mdn-api_element_mouseover_event
{'source': 'GithubIssues', 'repo_name_with_owner': 'Fyrd/caniuse', 'issue_id': 197631324, 'repo_stars': 5399.0}