Certify v3.0.0

[maennchen]

Part of #221

Tasks

• [x] Pass Certifications
• [x] ErlEF Join OpenID Foundation - https://openid.net/foundation/benefits-members/ - @sstrollo
• [x] Buy Certification for this year - https://openid.net/certification/fees/ - @sstrollo
• [x] Submit - @maennchen - Reference OCS-1383
• [x] Await Result - @maennchen
• [ ] Uncomment Certification Details in README - @maennchen