We are formally separating network adapters from our MoPub SDK. This is to enable an independent release cadence resulting in faster updates and certification cycles. New mediation location is accessible here.
We have also added an additional tool, making it easy for publishers to get up and running with the mediation integration. Check out https://developers.mopub.com/docs/mediation/integrate/ and integration instructions at https://developers.mopub.com/docs/android/integrating-networks/.