Mirror for code, installation packages and update check backend

[vladimiry]

There have been noisy stories of GitHub flagging accounts. If interested, see here and here the cases happened this week.

I don't believe this project is popular enough for GitHub's CEO to personally jump in and sort out the account flagging case like happened here. So I think this would be a good idea to have mirrors for code, installation packages, and update check backend. So there is a need to explore the options. Ideally, those would be hosted (no maintenance required), privacy respected, free for open-source projects and reliable options.

Listing previously raised related issues (CC @bruceleerabbit, @trymeouteh):

• Website #52
• leave Github #193
• Use GitHub Actions instead of Travis/Appveyor systems #267

---

Update check url is currently listed in config.json file and pointed to https://api.github.com/repos/vladimiry/ElectronMail/releases by default.

ElectronMail/src/shared/util.ts

Lines 54 to 56 in 9fe24e2

	updateCheck: {
	releasesUrl: "https://api.github.com/repos/vladimiry/ElectronMail/releases",
	proxy: "",

I think we could start from turning releasesUrl to the array and then the app would (one option to be chosen):

• Request the URLs starting from the first item. Stop requesting remaining URLs if the releases list successfully received.
• Request all the URLs in parallel and notify the newer versions from all the requested URLs. This could be useful if the account gets locked but remains accessible (turned to read-only mode).

[vladimiry]

There is a service that keeps the github repositories backed up. Here is the link to my github repositories https://gitbackup.org/#/user/vladimiry. A more comprehensive solution will be required though.