Add config.isDemo()

src/config.js

@@ -33,6 +33,7 @@ exports = module.exports = {
     zoneName: zoneName,
 
     isDev: isDev,
+    isDemo: isDemo,
 
     // for testing resets to defaults
     _reset: _reset
@@ -209,6 +210,10 @@ function isDev() {
     return /dev/i.test(get('boxVersionsUrl'));
 }
 
+function isDemo() {
+    return get('isDemo') === true;
+}
+
 function provider() {
     // FIXME this fallback is only there because old Cloudrons do not have the provider set till the next upgrade
     return get('provider') || 'caas';