added the following docs:
  - changelog
  - contributing
  - roadmap

modified license to reflect my name
modified readme to show more info

added to gitlab ci yaml file:
  - build template + jobs for release branch. release branch jobs will
    push to both gitlab and docker hub registries.
  - add echo $DOCKER_HUB_ORG/$CI_PROJECT_NAME:$SUFFIX_TAG just to show if
    the "tag" for docker hub is correct. will be removed later

modifications to gitlab ci yaml file:
  - changed ./.gitlab-ci.yml to .gitlab-ci.yml