Hello, according to blog posts v3 was removed in February of this year. Move over to V5 (Kraken) or if you’re alright with limited endpoints, to alleviate the need to refactor in November, use Helix!
You need to migrate your code to use v5. On February 14, 2017, we will be removing v1 and v2 of the API and transition v3 into a deprecated state. In one year (February 14, 2018), v3 will be removed from the API. We hope that this gives enough transition time for your integrations. - Source: https://blog.twitch.tv/action-required-twitch-api-version-update-f3a21e6c3410
Kraken Docs:
Helix Docs:
Release Notes:
Be sure to research before committing to Helix, though, there are many endpoints still missing, but bare in mind that Kraken will no longer be in service as of December.