should use the latest sim-launcher version

## motivation

We create a lot of SimLauncher.Launcher instances.  The sim_launcher gem was putting:

```
Using installed ios-sim at /usr/local/bin/ios-sim
```

Which was confusing users when trying to launch with instruments; "Why am I using ios-sim when I am launching with instruments?"

https://github.com/moredip/Sim-Launcher/pull/30