^([0-9]+)\.([0-9]+)\.([0-9]+)(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?(?:\+[0-9A-Za-z-]+)?$
^([0-9]|[1-9][0-9]*)\.([0-9]|[1-9][0-9]*)\.([0-9]|[1-9][0-9]*)(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?(?:\+([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?$
- Semantic versioning http://semver.org/
- Source of the regex npm/node-semver#32