Add docker container definition

Change-Id: If32020e6b8e8bb816eb54533554b18cc5302b5c9
diff --git a/php/security.php b/php/security.php
index 9842f3b..7f441ca 100644
--- a/php/security.php
+++ b/php/security.php
@@ -30,7 +30,7 @@
 
 		$credentials = new Credentials();
 
-		$query = $conn->prepare("SELECT id, password FROM ".$credentials->usersdb." WHERE id = ?");
+		$query = $conn->prepare("SELECT id, password FROM ".$credentials->usersdb()." WHERE id = ?");
 		$query->bind_param("i", $id);
 
 		$query->execute();