Added changelog

Author: k1o0

CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+## [Latest](https://github.com/cortex-lab/matlab-ci/commits/master)
+
+### Added
+
+- changelog
+- status and coverage endpoints for shields
+
+### Modified
+
+- changed from using Smee client to Serveo for exposing ZTEST
+- fixes for test reports endpoint
+- tests now performed only on head commit