Simple test for sidejob_supervisor.
[bug fix] fixed sidejob_supervisor:spawn/4

Counterexample:
  [{set,{var,1},{call,sidejob,new_resource,[resource,sidejob_supervisor,1,1]}},
   {set,{var,7},{call,supervisor_eqc,work,[spawn_mfa,1]}}]

  sidejob:new_resource(resource, sidejob_supervisor, 1, 1) ->
    {ok, <0.19634.1>}
  supervisor_eqc:work(spawn_mfa, 1) -> timeout

  Reason: {postcondition, {not_pid, timeout}}