Update CHANGELOG for v1.0.6

***NO_CI***

Author: nfbot

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Change Log
 
+## [**Changes available only in 'Preview' NuGet packages:**](https://github.com/nanoframework/lib-nanoFramework.System.Net/tree/HEAD)
+
+[Full Changelog](https://github.com/nanoframework/lib-nanoFramework.System.Net/compare/v1.0.5-preview-001...HEAD)
+
+**Documentation and other chores:**
+
+- Bumps nanoFramework.Runtime.Events from 1.0.5-preview-003 to 1.0.5-preview-007 [\#63](https://github.com/nanoframework/lib-nanoFramework.System.Net/pull/63)
+
 ## [v1.0.5-preview-001](https://github.com/nanoframework/lib-nanoFramework.System.Net/tree/v1.0.5-preview-001) (2019-03-07)
 [Full Changelog](https://github.com/nanoframework/lib-nanoFramework.System.Net/compare/v1.0.3-preview-009...v1.0.5-preview-001)