User Story 5, All user names are links to a show page

[BrianZanti]

As a visitor
With the exception of a user's show page,
Anywhere I see a user's name on the site for a book review,
I can click on the name to go to that user's show page.

DO THESE STORIES FIRST:

• User Story 16, User Show Page

Checklist:

• base code tests are written
• base code is written to pass tests
• edge case ("sad path") tests written
• edge case code written
• code is reviewed
• branch is merged
• all tests still pass

child of #31

child of #33

depends on #11