[Suggestion] It seems dangerous that requests api for contributor in this way

[currybob]

Our contributor could change their name every moment.
But, Like PR #219 , if contributors change their name, API not works properly, because Promise.all returns just reject if any of Promise array rejects result.

So now we would decide the way it reflects

I tried this way to avoid "fast-fail-behavior" in Promise.all and it works
Please review it at #220 @gimdongwoo @thomasJang @aeei