Don't blindly succeed even when you fail

- must use a non-zero exit code to signify failure to Concourse

ci/tasks/check-dns.rb

@@ -16,6 +16,8 @@ def get_whois_nameservers(domain)
   nameservers
 end
 
+exit_code=0 # assume successful exit
+
 check_domain(domain)
 puts "[PASS] #{domain} basic check ('DOMAIN' variable set & not empty)"
 
@@ -30,6 +32,9 @@ whois_nameservers.each do |whois_nameserver|
     puts "[PASS] #{whois_nameserver}'s NS records match whois"
   else
     puts "[FAIL] #{whois_nameserver}'s NS records do NOT match whois: #{dig_nameservers.join(", ")}"
+    exit_code=5
   end
   #p "#{whois_nameserver}: #{nameservers}"
 end
+
+exit(exit_code)