Change class for the Photo Gallery component to be more specific

[adamjohnson]

Steps to reproduce the issue

Right now, the Photo Gallery component uses a pretty generic class of .photos to trigger the Magnific Popup gallery.

Results

The .photos class is very generic and can lead to confusion if someone were using this component but wanted to use it in a different way (see Reed Innovation's Events page).

Expected results

If we changed the class to something like .js-wvu-lightbox-gallery, I don't think we'd see confusion or style/script conflicts.

How to fix

Since many people use the photo gallery component in the wild, does it make sense to make a new v2 partial or can we just change the .photos class to .js-wvu-lightbox-gallery and be done?

My initial thought is that we could change the class—but let me know if I'm incorrect here.