MyCelo: Complete migrations on

[trianglesphere]

The ones left are attestations, validators, governance

[oneeman]

@trianglesphere @mcortesi One problem until this is done is that celocli network:contracts can't be used (it will exit with an error). For now I guess the way to go is to save the output of the genesis step, since it lists the contracts' addresses.

This may also be a blocker for #1383 and/or #1384. There may be ways to work around it, such as deploying those migrations separately after the testnet is running, but I'm guessing it'd be easier to just do this one first.

[oneeman]

Branch is https://github.com/celo-org/celo-blockchain/tree/oneeman/mycelo-missing-contracts . @mcortesi will do the 25_elect_validators migration

[oneeman]

@mcortesi I pushed the attestations and governance migrations. For governance, I skipped setting the constitution thresholds and transferring core contract ownership, as in all the existing configs in celo-monorepo we are skipping those steps. Adding the ownership transfer would be easy and quick if we want to later on. Support for a constitution would be more tedious. I'm going to reassign this issue to you as you're working on the ElectValidators migration.

[oneeman]

This has already been finished in #1409