Add border radius and shadow to project avatar on project home page

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/pages/projects.scss

@@ -38,6 +38,11 @@
       font-size: 45px;
       line-height: 1.6;
     }
+
+    .avatar, .identicon {
+      @include border-radius(4px);
+      box-shadow: 0 1px 2px #ddd;
+    }
   }
 
   .project-home-dropdown {