check for no links in link file and fail if not pull request

build/validate_links.rb

@@ -17,6 +17,10 @@ raw_links.each do |link|
         links.push(link)
     end
 end
+if links.length <= 0
+    puts "no links to check"
+    exit(0)
+end
 fails = []
 # Fail on any duplicate elements
 dup = links.select{|element| links.count(element) > 1}