npm run package should build for all the platforms

[vlad-shatskyi]

Currently the package script

rm -rf '/Applications/Black Screen.app'; electron-packager . 'Black Screen' --platform=darwin --arch=x64 --version='0.30.0' --out='/Applications' --icon='./icon.icns'

is very platform dependent.

Perhaps, it's worth looking into how Atom or other Electron projects are being packaged.

[G07cha]

We can use gulp-if for this or just create separate scripts for Unix and non-Unix system

[vlad-shatskyi]

https://github.com/maxogden/electron-packager supports builds for different platforms out of the box. Maybe there are better tools.

[G07cha]

For production build we can use 'all' for platform and arch options, and for development provide specific scripts.

[vlad-shatskyi]

Let's try that.

[joshwiens]

@ShockOne @G07cha - This task fits well with #63 and much like the CI & CD, I am happy to pick this one up