copyDocsVersion()

in gulpfile.js [374:383]


    copyDocsVersion('dev', NEXT_DOCS_VERSION, function (error) {
        if (error) {
            console.error(error);
            done();
            return;
        }

        // finally update the version file with the new version
        fs.writeFile(VERSION_FILE, NEXT_DOCS_VERSION + '\n', done);
    });