Update ruby version to 2.3.1 & 2.2.5 on travis
Update ruby version to 2.3.1 & 2.2.5 on travis

- https://www.ruby-lang.org/en/news/2016/04/26/ruby-2-3-1-released/
- https://www.ruby-lang.org/en/news/2016/04/26/ruby-2-2-5-released/
hlegius/model,hanami/model,pascalbetz/hanami-model,lotus/model,hanami/model,cllns/hanami-model