Unit Tests

- Removed obsolete references to 'synch.key'.

test/feature.print.empty.columns.t

@@ -59,12 +59,11 @@ $output = qx{../src/task test rc.print.empty.columns:yes rc:bug.rc 2>&1};
 like ($output, qr/Project/, 'non-empty \'project\' column is printed if rc.print.empty.columns:yes');
 
 # Cleanup.
-unlink qw(pending.data completed.data undo.data backlog.data synch.key bug.rc);
+unlink qw(pending.data completed.data undo.data backlog.data bug.rc);
 ok (! -r 'pending.data'   &&
     ! -r 'completed.data' &&
     ! -r 'undo.data'      &&
     ! -r 'backlog.data'   &&
-    ! -r 'synch.key'      &&
     ! -r 'bug.rc', 'Cleanup');
 
 exit 0;