chore: add a changelog

CHANGELOG.md

+
+# CHANGELOG
+
+## Version 0.2.0 (2020-10-01)
+### New features
+
+- assign merge request in a randomized order
+
+
+## Version 0.1.1 (2020-09-24)
+### Various changes
+
+- black: paint it black & add tox target
+- README.md: yaml code
+- show time
+
+