We built a immature version of ticat before call ti.sh,
it do support async/concurrent executing with a keyword go.
But in practices we found out that these were rarely used, it has limited demands.
So we decide not to support async/concurrent executing in ticat for now. Once we need them we will provide them.
Components can do async executing by themselves now, an example:
$> ticat bench.async-run : ... : ... : bench.wait-async