Update system requirements

docs/System Requirements.md

@@ -10,12 +10,12 @@ The Business Apps are very lightweight on server resources.  The minimum support
 
 ### Software and Operating System
 
+We test and officially support the following configurations.
+
 * Server Operating System
     * Ubuntu
     * Debian
 * PHP
-    * 7.0
-    * 7.1
     * 7.2
 * Database
     * MySQL 5.7+
@@ -23,6 +23,8 @@ The Business Apps are very lightweight on server resources.  The minimum support
 * Web Server
     * Apache 2.4
 
+Other operating systems, web servers, and databases will likely function, but are not supported by Netsyms.  Older PHP versions are usually incompatible.
+
 ### Recommended Software
 For best performance, security, and ease of administration, we recommend installing the following on your server:
 
@@ -71,4 +73,4 @@ While we do not support the following browsers, they will likely still work.  Yo
 These browsers are known to lack support for CSS rules, JavaScript APIs, and other technology required to run the Business Apps.
 
 * Opera Mini
-* Internet Explorer
+* Internet Explorer