Remove unnecessary classes in header

Since the top-bar already includes a layout positioning the elements,
these classes are redundant and actually confusing, since the element
floating to the right was on the left.

This solves a problem where the outline wasn't correctly displayed when
focusing on the logo using the keyboard. Firefox was displaying two
vertical lines together above the logo, while recent Chrome versions
displayed the outline to the right of the logo.

app/views/layouts/_header.html.erb

@@ -11,7 +11,7 @@
   </div>
 
   <div class="top-bar">
-    <span data-responsive-toggle="responsive-menu" data-hide-for="medium" class="float-right">
+    <span data-responsive-toggle="responsive-menu" data-hide-for="medium">
       <button type="button" class="menu-button" data-toggle>
         <span class="menu-icon"></span>
         <%= t("application.menu") %>
@@ -20,7 +20,7 @@
 
     <h1 class="top-bar-title">
       <%= link_to root_path, accesskey: "0" do %>
-        <%= image_tag(image_path_for("logo_header.png"), class: "float-left", alt: setting["org_name"]) %>
+        <%= image_tag(image_path_for("logo_header.png"), alt: setting["org_name"]) %>
       <% end %>
     </h1>