class Hash

# => { "person" => { "name" => "Rob", "age" => "28" } }
hash.deep_stringify_keys

hash = { person: { name: 'Rob', age: '28' } }

nested hashes and arrays.
This includes the keys from the root hash and from all
Return a new hash with all keys converted to strings.

def deep_stringify_keys
  deep_transform_keys{ |key| key.to_s }
end