Add support for relative_url_root option.

This solves problem if you have set your application to be run on relative url like "/url/"
(`config.action_controller.relative_url_root` option).

app/views/api_taster/routes/show.html.erb

@@ -16,7 +16,7 @@
   <% end %>
 
   <% @params.each do |param| %>
-    <%= form_tag @route[:path], :method => @route[:verb], :class => 'well form-horizontal', :remote => true do %>
+    <%= form_tag @route[:full_path], :method => @route[:verb], :class => 'well form-horizontal', :remote => true do %>
 
       <% if param[:url_params].empty? && param[:post_params].empty? %>
         <div class="alert alert-info">

lib/api_taster/route.rb

@@ -116,12 +116,14 @@ def discover_rack_app(app)
 
       def normalise_route(route, path_prefix = nil)
         route.verb.source.split('|').map do |verb|
+          path = path_prefix.to_s + route.path.spec.to_s.sub('(.:format)', '')
           {
-            :id   => @_route_counter+=1,
-            :name => route.name,
-            :verb => verb.gsub(/[$^]/, ''),
-            :path => path_prefix.to_s + route.path.spec.to_s.sub('(.:format)', ''),
-            :reqs => route.requirements
+            :id        => @_route_counter+=1,
+            :name      => route.name,
+            :verb      => verb.gsub(/[$^]/, ''),
+            :path      => path,
+            :full_path => rails_url_root + path,
+            :reqs      => route.requirements
           }
         end
       end
@@ -143,6 +145,10 @@ def hash_diff(h1, h2)
           h2[k] == v
         end.merge!(h2.dup.delete_if { |k, v| h1.has_key?(k) })
       end
+
+      def rails_url_root
+        ActionController::Base.relative_url_root.to_s.chomp('/')
+      end
     end
   end
 end