A new patch, MDVA-532, enables merchants using Magento Community Edition 2.0.x to upgrade to Magento 2.1 Community Edition Release Candidates or GA software. More information about the patch and important instructions for command-line upgrades to Magento 2.1 when sample data is installed are available in a technical bulletin posted at http://devdocs.magento.com/guides/v2.0/release-notes/tech_bull_21-upgrade.html.