Convert releaser into module

.gitignore

.gitlab-ci.yml

.gitlab/release_template.md

.gitlab/releaser.py

.gitlab/releaser/__init__.py

.gitlab/releaser/__main__.py

.gitlab/releaser/artifact.py

.gitlab/releaser/binartifact.py

.gitlab/releaser/fsitemsize.py

.gitlab/releaser/job.py

.gitlab/releaser/pipeline.py

.gitlab/releaser/placeholder.py

.gitlab/releaser/projectapi.py

.gitlab/releaser/releasenote.py

.gitlab/releaser/releaser.py

.gitlab/releaser/releasewikipage.py

.gitlab/releaser/sourceartifact.py

.gitlab/releaser/template.py