Update ComposerInformation for Mage-OS vendor name

[Vinai]

The class Magento\Framework\Composer\ComposerInformation needs to be updated so it checks for the vendor name mage-os instead of magento.

Preconditions and environment

• Mage-OS 1.0.0 preview

Steps to reproduce

Log into the admin and inspect the footer.

Expected result

I expect to see the Mage-OS ver. 1.0.0.

Actual result

I see Mage-OS ver. UNKNOWN.

Additional information

There are a number of regular expressions that need to be updated so they match the vendor-name mage-os:

• \Magento\Framework\Composer\ComposerInformation::getRequiredPhpVersion
• \Magento\Framework\Composer\ComposerInformation::isSystemPackage
• \Magento\Framework\Composer\ComposerInformation::isMagentoRoot

Also, the tests in dev/tests/integration/testsuite/Magento/Framework/Composer/ComposerInformationTest.php need to be adjusted accordingly.