fix(private-modules): fix versioning private modules.

[amurdock]

affects: lerna-semantic-release-get-last-release, lerna-semantic-release-io

Fix versioning private modules with minor and patch values.

[amurdock]

Currently when you're trying to version a private module the implementation always defaults to an initial release. This bumps the major version of the module and doesn't tag the release.

Unfortunately there's a bug in packages/lerna-sematic-release-io/io/git.js in that clients of revParse pass the version they're interested in however the implementation doesn't pass this onto simple-git.

Finally simple-git accepts a collection of versions and returns them as a \n delimited set of hashes ... however lerna-semantic-release-get-last-release expects the one and only hash it's interest in. A simple .split('\n')[0] sorts this.

[KingScooty]

When is this getting merged in? I was just about to use this tool on a private module, but i might need to hold off if this isn't getting merged in any time soon.