Decide what to do w/ mapstructure library

[codeboten]

The library is going to be deprecated and a few options for existing forks are coming up. Should we move to another fork, fork it ourselves?

See mitchellh/mapstructure#349

[codeboten]

One of the options for existing forks: https://github.com/go-viper/mapstructure

[mx-psi]

Trying to get #6671 fixed upstream and seeing how it goes could be a good test to see how receptive the new owners are to our use case

[atoulme]

I am offering that we switch over to the fork which will be maintained moving forward: #9634

[TylerHelmuth]

Since we've taking the forked version can we close this issue?

[mx-psi]

Will close it once we merge #9635, which fixes one of the things we were considering when tackling this issue