use command-line option first for configuration file location

bin/update-metadata

@@ -29,7 +29,10 @@ GetOptions(
     -verbose => 0
 );
 
-my $configuration_file = $ENV{ACCESS_CHECK_CONFIG} || 'conf/manager.conf';
+my $configuration_file =
+    $options{configuration}   ||
+    $ENV{ACCESS_CHECK_CONFIG} ||
+    curfile()->dirname()->sibling('conf', 'manager.conf');
 my $configuration = Config::Tiny->read($configuration_file);
 if (!$configuration) {
     die Config::Tiny->errstr() . "\n";