Generalize the type for `sequence` taking a dict
Generalize the type for `sequence` taking a dict

There wasn't actually any real reason to limit this to working on
`[String: Decoded<T>]` values. Instead, we should be able to use this
function with any key type.

ojolabs/Argo,thoughtbot/Argo,thoughtbot/Argo,ojolabs/Argo,ojolabs/Argo,thoughtbot/Argo