improve docs

Author: mevdschee

README.md

@@ -826,11 +826,13 @@ The following types of 404 'Not found' errors may be reported:
 
 I am testing mainly on Ubuntu and I have the following test setups:
 
-  - Ubuntu 12.04 Server with PHP 5.3 and MySQL 5.6 (ondrej PPA)
-  - Ubuntu 14.04 Server with PHP 5.5 and MySQL 5.6
+  - Ubuntu 12.04 Server with PHP 5.3 and MySQL 5.5 and PostgreSQL 9.1
+  - Ubuntu 14.04 Server with PHP 5.5 and MySQL 5.6 and PostgreSQL 9.3
+  - Ubuntu 16.04 Server with PHP 7.0 and MySQL 5.7 and PostgreSQL 9.5
+  - Debian 7 Server with PHP 5.4 and MySQL 5.5 and PostgreSQL 9.1
+  - Debian 8 Server with PHP 5.6 and MariaDB 5.5 and PostgreSQL 9.4
+  - CentOS 7 Server with PHP 5.4 and MySQL 5.5 and PostgreSQL 9.2
   - Windows 2012 R2 with PHP 5.6 and SQL Server 2012
-  - Ubuntu 16.04 Desktop with PHP 7.0 and MariaDB 10.0
-  
 
 This should cover most environments, but please notify me of failing tests and report your environment.