Mesur.io needs to update issuer to latest VC-API options

[Andrew Jones]

https://github.com/w3c-ccg/vc-api-test-suite-implementations/blob/b95d0a73c635031584c14b16373d5e7a1feae5f2/implementations/Mesur.io.json#L14-L16

Mesur.io still needs an options object with type: Ed25519Signature2018 passed to their issuer.
options.type is no longer in the VC-API https://w3c-ccg.github.io/vc-api/#issue-credential except in the context of credentialStatus.

[BigBlueHat]

Related to #81. Not sure what the status is/should be. @brownoxford would love to catch-up with what y'all need/want here.

Thanks!
🎩

[Tashi D. Gyeltshen]

Closing, since mesur.io is no longer in the implementations' list.