Typo in TestScheduler.ts

[wildcardalice]

Just a heads up, there's a typo here (twice on the same file): https://github.com/ReactiveX/rxjs/blob/master/src/internal/testing/TestScheduler.ts#L86

"Ommitted" -> "Omitted"

[cartant]

PRs that fix typos - however small - are always welcome and will be merged with a "thank you." 🙂