Increase more than one unit of version level at once

It could exist a command line to increase version level more than one unit
For example:
    $ stepup version
    v2.0.3.rc10+2

```
$ stepup version create --level major --increase 3
v5.0.0
```

The purpose would be to provide an initial use of the gem in a late stage of a project or even a way to manage an strategic decision of the project owner to increase version levels at once
