The output of Errors::BoxRemoveMultiVersion is now like
the output of Errors::BoxRemoveVersionNotFound. I think
that's expected.
example output without this patch:
```
$ vagrant box remove berendt/ubuntu-14.04-amd64
You requested to remove the box 'berendt/ubuntu-14.04-amd64' with provider
'virtualbox'. This box has multiple versions. You must
explicitly specify which version you want to remove with
the `--box-version` flag.
Versions: * 0.2.11
* 0.2.12
* 0.2.14
```
example output with this patch:
```
$ vagrant box remove berendt/ubuntu-14.04-amd64
You requested to remove the box 'berendt/ubuntu-14.04-amd64' with provider
'virtualbox'. This box has multiple versions. You must
explicitly specify which version you want to remove with
the `--box-version` flag. The available versions for this
box are:
* 0.2.11
* 0.2.12
* 0.2.14
```
8f96205d95