Add event.completed logic to all-events page
Add event.completed logic to all-events page

* show completed event with green background
* don't show event's ID
* instead slug in the first place
* show completness or lack of it in the next-to-last column

pbanaszkiewicz/amy,wking/swc-amy,vahtras/amy,wking/swc-amy,swcarpentry/amy,swcarpentry/amy,swcarpentry/amy,vahtras/amy,wking/swc-amy,vahtras/amy,wking/swc-amy,pbanaszkiewicz/amy,pbanaszkiewicz/amy