fixed version output

Using this tool the first time I got the following output.

```bash
vagrant@precise64 (master) $ semver-bump
Current version is: 0.1.0vagrant@precise64 (master) $
```

Now it looks like that.

```bash
vagrant@precise64 (fix-version-output) $ semver-bump
Current version is: 1.0.0
vagrant@precise64 (fix-version-output) $ semver-bump version
Semantic Versioning Bumper v1.0.0
```

I am not sure how you use the output stream, that is why I created the PR. Would be cool if the output is formatted more properly.

Further question, why differs both shown versions by the character `v`?