changelog: update 20.2-45-g5f7825e2-0ubuntu1~19.10.1 for release

changelog: update 20.2-45-g5f7825e2-0ubuntu1~18.04.1 for release

changelog: update 20.2-45-g5f7825e2-0ubuntu1~16.04.1 for release

changelog: cloud-init.templates: correct lintian issue missing RbxCloud

changelog: drop six, unittest2, nose, pep8 and pyflakes from build-deps

releasing cloud-init version 20.2-38-g8377897b-0ubuntu1~16.04.1

releasing cloud-init version 20.2-38-g8377897b-0ubuntu1~20.04.1

releasing cloud-init version 20.2-38-g8377897b-0ubuntu1~19.10.1

releasing cloud-init version 20.2-38-g8377897b-0ubuntu1~18.04.1

releasing cloud-init version 20.2-38-g8377897b-0ubuntu1