use command-line option first for configuration file location

bin/access-check-manager.pl

@@ -46,7 +46,10 @@ pod2usage(
     -verbose => 0
 ) unless $action;
 
-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";