Debian Support

1. Create a 2-master branch from master and push it to GitHub. Add protection from force pushing.
2. Use the instructions[0] in pulp_template to bootstrap pulp_deb for Pulp 3.
3. Replace all files on the master branch with the content created in 2 ^.
4. Disable protection from force pushing to master branch.
5. Push master branch to GitHub.
6. Re-enable protection from force pushing on master.
7. Notify pcreech in #pulp-dev to let him know that pulp_deb should be built from the 2-master branch in the future.
8. Update the jenkins job definition[1] and replace master with 2-master so unit tests continue to run on pulp 2 PRs.
9. Notify a red-hatter to update the Jenkins job withthe new job definition.

[0] https://github.com/pulp/plugin_template/blob/master/README.rst#bootstrap-a-new-pulp-plugin
[1] https://github.com/pulp/pulp-ci/blob/master/ci/jjb/jobs/projects.yaml#L165