fix(async): let async exception of deadline can be caught

[justjavac]

try {
  await deadline(Promise.reject("booom"), 20);
} catch (error) {
  console.log(`catch error: ${error}`);
}

will crash:

catch error: booom
error: Uncaught (in promise) booom

[bartlomieju]

@justjavac looks good, could you add a test case that exercises provided example?

[justjavac]

done

[ry]

LGTM - thanks @justjavac