enable json API by default. (sns_config.yml) (fixes #2889)
enable json API by default. (sns_config.yml) (fixes #2889)

isaosano/OpenPNE3,isaosano/OpenPNE3,ShinichiU/OpenPNE3,ShinichiU/OpenPNE3,kashiwasan/symfony-advanced,upsilon/travis-test,ShinichiU/OpenPNE3,ShinichiU/OpenPNE3,upsilon/travis-test,isaosano/OpenPNE3,C-nakajima/OpenPNE3,C-nakajima/OpenPNE3,isaosano/OpenPNE3,C-nakajima/OpenPNE3,kashiwasan/symfony-advanced,nishizoe/OpenPNE3,nishizoe/OpenPNE3,C-nakajima/OpenPNE3