Routes have been refactored

Dashboard routes have been refactored. Now instead of having resources
for dashboard and routes inside a dashboard namespace the proposal
routes contain a dashboar singleton containing everything related to it.

app/views/proposals/share.html.erb

@@ -33,7 +33,7 @@
               <strong><%= t('.improve_it') %></strong>
             </p>
             <div class="centered">
-              <%= link_to t('.dashboard'), proposal_dashboard_index_path(@proposal), class: 'button' %>
+              <%= link_to t('.dashboard'), proposal_dashboard_path(@proposal), class: 'button' %>
             </div>
           </div>
         <% end %>