promise: Add check_surykatka_json

A promise to check json output of surykatka:

https://lab.nexedi.com/nexedi/surykatka
3 jobs for <span class="ref-name">feature/promise-check-surykatka-json</span> in 0 seconds
Status Job ID Name Coverage
  External
failed SlapOS.Eggs.UnitTest-luke.Python2

00:30:25

passed SlapOS.Eggs.UnitTest-luke.Python3

01:01:49

passed SlapOS.Eggs.UnitTest-luke.Python2

00:53:44