Log Message:
www/ruby-loofah: update to 2.5.0

Update ruby-loofah to 2.5.0.

## 2.5.0 / 2020-04-05

### Features

* Allow more CSS length units: "ch", "vw", "vh", \ 
"Q", "lh", "vmin", "vmax". [#178] \ 
(Thanks, @JuanitoFatas!)

### Fixes

* Remove comments from `Loofah::HTML::Document`s that exist outside the `html` \ 
element. [#80]

### Other changes

* Gem metadata being set [#181] (Thanks, @JuanitoFatas!)
* Test files removed from gem file [#180,#166,#159] (Thanks, @JuanitoFatas and \ 
@greysteil!)