Update electron and electron-builder to latest stable versions

[Ariandr]

I updated electron to latest v.6.0.1 and electron-builder to v.21.2.0. It's also compatible with electron-packager (which supports electron 6.0.+). I tested building both variants.

But as for me, it's better to deliver the app using electron-builder, because it creates installable .dmg file for macOS and generates files for Windows & Linux. Also, it might solve issues like https://github.com/onmyway133/PushNotifications/issues/19 in comparison with electron-packager.

Important: For building with electron-builder you need to run npm run dist. Generated files end up in the folder dist. For building with electron-packager you need to run npm run release. Generated files end up in the folder PushNotifications-darwin-x64.

[Ariandr]

Hi @onmyway133 Please, review and merge if everything is ok. I tested on my side, works without issues.

[onmyway133]

@Ariandr Thanks for the PR 👍 Can you help uploading build artifacts to release?

[Ariandr]

@onmyway133 Yes, I will.

[Ariandr]

@onmyway133 I also updated README in order to let people know how they can build the app themselves to solve issues like https://github.com/onmyway133/PushNotifications/issues/17 & https://github.com/onmyway133/PushNotifications/issues/19

[onmyway133]

@Ariandr 👍 awesome

[Ariandr]

Hi @onmyway133 Let me know, when you create a new release. I'm available to add Windows & Linux artifacts.

The only issue I noticed is the increase of the size of output files. E.g., for v.1.4.0 the files are ~50 MB in size on macOS, for v.1.4.1, the files are ~500 MB built with electron 6.0.1. It's relevant for artifacts built both with electron-packager and electron-builder and then archived.

I also checked it with electron 5.0.0. Unfortunately, it's even worse, ZIP file weighs 1.76 GB!

Do you have any ideas why it happened? Maybe it's not only the issue of electron on its own? Or maybe you have other sizes on your machine?

[onmyway133]

@Ariandr No, I don't have that problem. The zip file, at least for macOS is less than 100MB. By the way, I just created release 1.5.0 https://github.com/onmyway133/PushNotifications/releases/tag/1.5.0

[Ariandr]

@onmyway133 Great! I downloaded the code again and the build sizes are back to normal. I added macOS files to release artifacts and will add the Windows file today-tommorow.

[onmyway133]

@Ariandr awesome 👍 I thank you on Twitter https://twitter.com/onmyway133/status/1161602721834831872?s=20 but don't know your handle

[Ariandr]

@onmyway133 Thank you for mentioning me :) Though, I don't feel that I've done much at all. Just little things ))