CHANGED: Updated hash generation to use Sqids rather than HashIds

[tarellel]

Summary:

Convert prefixed_ids from using hashids to use Sqids as its new hashing library.

Context:

https://github.com/peterhellberg/hashids.rb

Hashids has been rebranded to 🦑 Sqids, and there is a Ruby implementation of it that I suggest you use instead of Hashids.rb

Notes:

Since this is a possible breaking change, particularly with salting; even if the changes aren't significantly large it probably deserves a minor/major version bump as well.

[excid3]

Yeah, I already started this a while back but held off because it's not backwards compatible. All links using prefixed IDs will be broken and I think we need to be careful with that.