Option to skip update-check

[alexgit2k]

Every time deployer is started it checks if there is an update available (except for execution plans):

deployer/src/Command/MainCommand.php

Lines 163 to 170 in 507f54c

	private function checkUpdates()
	{
	try {
	fwrite(STDERR, Httpie::get('https://deployer.org/check-updates/' . DEPLOYER_VERSION)->send());
	} catch (\Throwable $e) {
	// Meh
	}
	}

I would like to have an option like --skip-updatecheck to skip the update-check.