v0.0.4: Now with 100% less MultiJson

Don't depend on MultiJson, as it doesn't help performance-wise and it's easy to swap the JSON backend anyway. For example, if you were to change to Yajl:

require "yajl"
Granola.json = ->(obj, **opts) { Yajl::Encoder.encode(obj, opts) }

See #1 for context.

❤️ ❤️ ❤️ Thanks @djanowski and @guilleiguaran for bringing this up! ❤️ ❤️ ❤️