Add Last Time User Visited an Archive Data

[dsu1]

It would be good to keep track of the last time the user visited an archive.

To implement this:

• Perform a database migration, adding a 'last viewed' column to the Archive table, this will be a Date type
• In a the Archive's Show action, add and update the 'last viewed' field with Time.now
• Display the last time the user visited an archive in the Archive Index page, this information isn't really relevant within the Archive Show view
  • This will be added to the partial that generates the archive boxes