Merge branch 'add-changelog' into 'master'

Add CHANGELOG

Closes #12

See merge request !10

CHANGELOG.md

+# Changelog
+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).
+
+## [1.0.0] - 2020-07-16
+### Added
+ - PEP8: Added a [CI template job](https://gitlab.developers.cam.ac.uk/uis/devops/continuous-delivery/ci-templates/-/blob/master/auto-devops/pep8.yml) to check for [PEP8](https://www.python.org/dev/peps/pep-0008/) violations in Pyhon files. The CI template generates junit.xml reports that feed back to [GitLab CI](https://docs.gitlab.com/ee/ci/junit_test_reports.html) for interpretation and storage as artifacts. The PEP8 CI template job uses the python tool flake8.