Fix PHP 7 signature

src/Handler.php

@@ -195,10 +195,10 @@ class Handler extends BaseHandler {
    * @param null $key
    *   Optional name of an option to be received instead of the full set of options.
    *
-   * @return array
+   * @return array|string
    *   The options.
    */
-  public function getOptions($key = NULL): array {
+  public function getOptions($key = NULL) {
     if ($this->options === NULL) {
       $env = new Dotenv('docker4drupal', $this->io);
       $projectname = getenv('COMPOSE_PROJECT_NAME');