Fail rake spec if untested payloads

MSP-11145

Add action to spec task that will cause spec to exit(1) if
log/untested-payloads.log exists.  The untested payloads are then
printed with instructions of which spec to update.

Rakefile

@@ -9,3 +9,20 @@ require 'metasploit/framework/require'
 Metasploit::Framework::Require.optionally_active_record_railtie
 
 Metasploit::Framework::Application.load_tasks
+
+# append action to run after normal spec action
+task :spec do
+  untested_payloads_pathname = Pathname.new 'log/untested-payloads.log'
+
+  if untested_payloads_pathname.exist?
+    $stderr.puts "Untested payload detected.  Add tests to spec/modules/payload_spec.rb for payloads classes composed of the following payload modules:"
+
+    untested_payloads_pathname.open do |f|
+      f.each_line do |line|
+        $stderr.write "  #{line}"
+      end
+    end
+
+    exit 1
+  end
+end