Basic pipenv workflow
Please build on the existing project structure so that the following README instructions work as expected:
pipenv install --dev -e .
# should create a virtualenv based on this repo
pipenv run bosun --help
# should return a message:
# "Bosun is a GitLab bolt-on for Liberty-style project management."
pipenv run bosun greet world
# should invoke the method "world_greet()"
# and print the message "Hellow world!"