Fixes link_to in user partial

Hi, cuducos. Was just a small issue. Hope the explanation in the commit helps:

Your `link_to` had only one argument. In that case, that one argument is meant to be a URL, so it was rendering links like this:

<a href="/users">Mr. Delmer Luettgen</a>

instead of

<a href="/users/2">Mr. Delmer Luettgen</a>

What you really want is `link_to user.name, user`, where the first argument is the body of your anchor tag and the second is your href attribute. Note that Rails is able to resolve that link from the `user` object being passed in the second argument.

See [here](http://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-link_to) for all of `link_to`'s different signatures.

Cheers,
O-I