add print button to all detail views

app/views/crawlers/courses_crawler/show_detail.html.erb

@@ -1,6 +1,8 @@
 <% if @course != nil %>
   <%-# TODO parse more fields and style them appropriately -%>
   <h2>Course: <%= @course['title']['de'] %></h2>
+  <%= button_to "PRINT", '#', onclick: "print()" %>
+
   <h5><%= @course['courseType'] %> <%= @course['semesterCode'] %>, <%= @course['weeklyHours'] %> SWS, <%= @course['instituteCode'] %> <%= @course['instituteName']['de'] %> </h5>
   <%= button_to 'Add to favorites', action: :add_to_fav, number: @course['courseNumber'], semester: @course['semesterCode'] %>
   <% if @lecturers_names != nil %>