app/views/wannahelp/toggle.js.erb
console.log("toggled helped repo: <%= @repo_id %>!");
var el = $(".wanna-help-btn[data-id='<%= @repo_id %>']");
<% if @repo.is_being_helped_by?(current_user) %>
el.removeClass('btn-success');
el.addClass('btn-danger');
el.html('Remove');
<% else %>
el.removeClass('btn-danger');
el.addClass('btn-success');
el.html('Help!');
<% end %>