Facter module should return custom facts

The ansible facter module should also return puppet custom facts by
default.

system/facter.py

@@ -45,7 +45,7 @@ def main():
         argument_spec = dict()
     )
 
-    cmd = ["/usr/bin/env", "facter", "--json"]
+    cmd = ["/usr/bin/env", "facter", "--puppet", "--json"]
     rc, out, err = module.run_command(cmd, check_rc=True)
     module.exit_json(**json.loads(out))