Prepare release 3.8.0

CHANGELOG.md

 ## Changelog
 
+### 3.8.0
+  * Add proper support for perl modules (thanks @deligatedgeek)
+
 ### 3.7.0
   * Add support for Ubuntu 18.04 LTS (thanks @rogermartensson)
   * Improved support for Debian 9 (thanks @carlgarner)

metadata.json

 {
   "name": "jgazeley-freeradius",
-  "version": "3.7.0",
+  "version": "3.8.0",
   "author": "jgazeley",
   "summary": "Install and configure FreeRADIUS",
   "license": "Apache-2.0",