Add code to detect Ubuntu 18.04 in installer.

Author: Till Brehm

install/lib/install.lib.php

@@ -95,6 +95,10 @@ function get_distname() {
 				$mainver = current($mainver).'.'.next($mainver);
 			}
 			switch ($mainver){
+			case "18.04":
+				$relname = "(Bionic Beaver)";
+				$distconfid = 'ubuntu1804';
+				break;
 			case "17.10":
 				$relname = "(Artful Aardvark)";
 				$distconfid = 'ubuntu1710';

server/lib/classes/monitor_tools.inc.php

@@ -87,6 +87,10 @@ function get_distname() {
 				$mainver = $ver;
 			}
 			switch ($mainver){
+			case "18.04":
+				$relname = "(Bionic Beaver)";
+				$distconfid = 'ubuntu1804';
+				break;
 			case "17.10":
 				$relname = "(Artful Aardvark)";
 				$distconfid = 'ubuntu1710';