Add option to force relaunch always

[PhoneixS]

I think it could be a good addition to add an option to force the app relaunch always including when isn't really necessary.

Background story: When using this package to refresh my angular / electron-forge app, there is a problem with trying to reload the app because I think it tries to compile the root folder instead of the index.html. But if you relaunch the app instead of refreshing it does the work correctly. See the issue electron-userland/electron-compile#233.