Performance testing

[jd-lara]

After a chat with @odow and the recent progress with POI we discussed revisiting the use of POI in PowerSimulations.jl

I've created a simulation script to test the implementation of POI here https://gist.github.com/jd-lara/1866b602f56fdbbb8b80ff400ba37509

In the current version of PowerSimulations.jl it is easier to compare rebuild vs parameters with a single flag.

[guilhermebodin]

In your tests is it working properly, faster than rebuilding the model form scratch?

We can add it to the performance tests of the package.