Remove collaborative legislation summary

This feature wasn't properly tested nor reviewed, and after reviewing
several pull requests with a similar status and considering this pull
request is related to the public area of the web, we've decided to
remove it before releasing version 1.1.

This commit reverts commit 4f50e67a.

app/models/abilities/everyone.rb

@@ -25,7 +25,6 @@ module Abilities
       can :new, DirectMessage
       can [:read, :debate, :draft_publication, :allegations, :result_publication,
            :proposals, :milestones], Legislation::Process, published: true
-      can :resume, Legislation::Process, &:past?
       can [:read, :changes, :go_to_version], Legislation::DraftVersion
       can [:read], Legislation::Question
       can [:read, :map, :share], Legislation::Proposal