🎨 decrease timeout for scheduling (TryGhost#7556)

refs TryGhost#7555
- temporary fix to make travis green
- that should not have a any bad effect on scheduling
- we just let the job awake a bit later
- the job logic is strong enough to catch the job if setTimeout awakes too late (that can happen, because setTimeout is not accurate)
- if (moment().diff(moment(Number(timestamp))) <= self.beforePingInMs) --> is smaller ensures that even if the diff is negative, it get's executed

core/server/scheduling/SchedulingDefault.js

@@ -170,7 +170,7 @@ SchedulingDefault.prototype._execute = function (jobs) {
                     });
                 });
             })();
-        }, diff - 200);
+        }, diff - 70);
     });
 };