Fix milestone publication date comparison

We're storing the publication date as datetime in the database, and we
were comparing it to a date, meaning today's milestones were not being
found.

app/models/milestone.rb

@@ -14,7 +14,7 @@ class Milestone < ApplicationRecord
   validates_translation :description, presence: true, unless: -> { status_id.present? }
 
   scope :order_by_publication_date, -> { order(publication_date: :asc, created_at: :asc) }
-  scope :published,                 -> { where("publication_date <= ?", Date.current) }
+  scope :published,                 -> { where("publication_date <= ?", Date.current.end_of_day) }
   scope :with_status,               -> { where("status_id IS NOT NULL") }
 
   def self.title_max_length