Seanmcm/update changelog0 17 insiders1 (#1867)

* Update changelog.md.

* Added the clang-format 6.0 update.

Author: sean-mcmanus

Extension/CHANGELOG.md

@@ -10,6 +10,7 @@
 * Fix `c_cpp_properties.json` requiring write access. [#1790](https://github.com/Microsoft/vscode-cpptools/issues/1790)
 * Change file not found in `compile_commands.json` message from an error to a warning. [#1783](https://github.com/Microsoft/vscode-cpptools/issues/1783)
 * Fix an IntelliSense crash during completion requests. [#1782](https://github.com/Microsoft/vscode-cpptools/issues/1782)
+* Update the installed clang-format to 6.0.
 
 ## Version 0.16.1: March 30, 2018
 * Fix random deadlock caused by logging code on Linux/Mac. [#1759](https://github.com/Microsoft/vscode-cpptools/issues/1759)