Add retries for failed requests

[tverona1]

It would be useful to add retries for failed requests.

Something like: https://github.com/FGRibreau/node-request-retry (for a drop-in replacement to request) or https://github.com/sindresorhus/got#retry (if moving to something other than request going forward).

Thanks!

[s0ph1e]

Hey @tverona1

Thank you for suggestion 👍
I'm not going to do it right now, but this improvement can be implemented during migration from request to some other library #401

[s0ph1e]

request was replaced with got in #445 and starting from next version v5 it will be possible to use retries by passing got options, e.g.

const options = {
	urls: [ 'http://example.com/' ],
	directory: testDirname,
	request: {
		throwHttpErrors: true,
		retry: {
			limit: 2,
			methods: ['GET'],
			statusCodes: [500]
		}
	}
};