with 100_000 records
       user     system      total        real
ActiveModel::Serializer  6.000000   0.130000   6.130000 (  6.168347)
Roar::JSON::JSONAPI 20.710000   0.240000  20.950000 ( 21.055724)
with 2000 records
       user     system      total        real
ActiveModel::Serializer  0.100000   0.010000   0.110000 (  0.102477)
Roar::JSON::JSONAPI  0.220000   0.000000   0.220000 (  0.219107)