Specificing 3 point version doesn't work (ex: v0.10.31.1)

I know boxen likes semantic versioning based on http://semver.org/ but nodejs use a more specific versioning numbers.

here is the output:

```
Error: Parameter version failed on Nodejs[v0.10.31.1]: Version must be like vN.N.N, not v0.10.31.1 at /opt/boxen/repo/shared/nodejs/manifests/version.pp:52
Wrapped exception:
Version must be like vN.N.N, not v0.10.31.1
```
