Update CHANGELOG to include 2.0.5 release notes

CHANGELOG.md

@@ -5,18 +5,20 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
+## [2.0.5] - 2019-06-07
 
 ### Added
 
 - Provide console output if stoQ configuration file does not exist (Thanks for feedback @jakubgs!)
 - Add command line option `--config-file` to define stoQ configuration file
 - Add command line option `--log-level` to allow for setting of the log level
+- Documentation for simplied method of defining plugin options within `__init__`
 
 ### Changed
 
-- Raise exception if installing a plugin that is already installed
+- Raise StoqPluginException if installing a plugin that is already installed
 - Display `plugin_path` when plugin is successfully installed
+- Raise StoqPluginNotFound when attempting to load non-existent or invalid plugin
 
 ## [2.0.4] - 2019-03-29