Trivial UI cleanup on individual posts

Both the clay css and templates/partials/post.html added a horizontal
rule at the top of each post footer (using the css border property and
hr respectively). Opted for using the clay css one as its used on
multiple pages (eg. blog pages and tag pages).

Signed-off-by: Collin J. Doering <collin.doering@rekahsoft.ca>

templates/partials/post.html

@@ -12,7 +12,6 @@
     </header>
     $body$
     <footer>
-      <hr>
       <div class='container'>
         <div class='eight columns alpha'>
           <a class='read-more' href='$url$'>See Comments</a>