Add Drone CI

- Add drone test environment
- Add drone config
- apt phpunit
- Fix api.php
- Fix item.php
- Fix DBStructure
- Check if caching is possible during tests

src/Database/DBStructure.php

@@ -12,7 +12,7 @@ use Friendica\Core\L10n;
 use Friendica\Core\Logger;
 use Friendica\Util\DateTimeFormat;
 
-require_once 'include/dba.php';
+require_once __DIR__ . '/../../include/dba.php';
 
 /**
  * @brief This class contain functions for the database management