Add Tracium to the dev list

[christian-bromann]

We at Sauce use Tracium to get the list of main thread tasks from a trace log.

[paulirish]

we're still in the process of developing porting tracium into LH as "tracehouse": aslushnikov/tracium#2

So we'll likely link that up instead. Let's keep this PR open as a reminder.

Thanks and good call, regardless :D

[Garbee]

Tracium hasn't been updated since it was published. I think regardless of LH getting it internally we can pretty much call it unmaintained.

Due to this I'm going to close this out to keep the repo a bit cleaner. If Aslushnikov is still maintaining it as-needed going forward and LH doesn't have this internally then I'm all for re-opening this to get added to the list.