Add HorizontalPodAutoscaler from kubernetes

[ElijahSey]

Add a new autoscaling pattern that simulates the kubernetes autoscaler.

It can be configured by setting a targetUtilization.

[franksn90]

@ElijahSey Looks mostly good. Just one thing: tolerance area returns immediately, meaning the remaining code is never executed. However, staying within minInstances and maxInstances should take precedence over reaching the targetUtilization. I suggest to fix that. I also suggest to move the comment about the motivation to the top of the class (javadoc).

As a side note: I noticed Kubernetes mentions different holdTimes for up- and downscaling, as well as a 30s evaluation frequency (MiSim probably evalutes every time unit. Thus, reacts faster.) You could add an explicit TODO or implement that behavior.