nativefier and installer seem to include dependencies twice

In the develop branch: nativefier produces .exe which, by size, seem to include the required R packages, and then these are again included in the installer from the `bin/` folder.

You do need at least R binary with shiny package (and its dependencies) installed to execute `shiny::runApp` (so this part has to stay out of the nativifier package). I'm not entirely sure but it might be that all other packages are possibly not necessary in the installer.