Proposal: don't store the version numbers

[jpnelson]

I think a lot of the complexity around git pushing / pulling

#74
#32

would be mitigated by a different approach – semantic release leaves 0.0.0-semantically-released in the package.json files.

I would propose committing code that has 0.0.0-semantically-released in the package.json files, and having a task lerna-semantic-release apply-versions that would apply the calculated version numbers, based on the current git history.

This apply-versions task would be run before bootstrapping, and the version numbers would be cleared (probably with a clear-versions task)

This would also partially solve the dry-run issue: #67