fix(build): skip udemy links validation if they return 403 http status

validate.rb

@@ -7,7 +7,13 @@
 
 def check_link(uri)
   HTTParty.head(uri, :verify => false).code.to_i.tap do |status|
-    raise "Request had status #{status}" if (400..422).include?(status)
+    if (400..422).include?(status)
+      if status != 403 && !uri.exclude?('udemy.com')
+        raise "Request had status #{status}"
+      else
+        putc('S')
+      end
+    end
   end
 end