Add example of installing a specific version
Support unpublishing a specific package version
Use packages url from config
Add unpublish spec
Simplify unpublish usage text
:lipstick: Use if/in
Only set ATOM_API_URL
Allow just a version to be specified
Always parse name when version specified
Merge pull request #158 from atom/ks-unpublish-version

Unpublish a specific package version