I tried to install the 0.3.0.5014-beta in contao 3.1.4 via the composer client (contao-legacy/cloud-api). The database update can not be executed (not via composer client nor the install tool), cause a call to a non-existing table is made before:
Fatal error: Uncaught exception Exception with message Query error: Table 'xxx.tl_cloud_api' doesn't exist (SELECT * FROM tl_cloud_api WHERE id=NULL LIMIT 0,1) thrown in ...\system\modules\core\library\Contao\Database\Statement.php on line 282