Users can add publications to journalists & see data on journalist index

Trello: https://trello.com/c/DAoRbGYz/50-journalists-have-publications

The user feature of "adding publications to journalists" includes being being able to view the associated data when viewing the journalist.

I recognize the Journalist model is approaching "fat" and could possibly be refactored in the future.

Update: DRY'd up Journalist model
``` erb
  <li>Publications: <%= abbreviate(journalist.publications, :name) %></li>
  <li>Topics covered: <%= abbreviate(journalist.topics, :name) %></li>
```