--to flag still prompting for user interaction

When we run a command using the `--to` flag (e.g. `ember-cli-update --to 3.26.1`), the output still prompts to ask which version we want:

```
? Blueprint updates have been found. Which one would you like to update? addon,
current: 3.20.0, latest: 3.27.0
```

Hitting enter a couple times moves past this prompt and produces the expected behavior (that is, it updates to the target version and not, say, latest), but I would expect that providing the `--to` option for `ember-cli-update` would preempt the need to ask the user this question. This becomes particularly important when attempting to use `ember-cli-update` as a codemod across multiple projects at the same time, or via an automated job. We want to be able to provide all the necessary information when the command is invoked, so that no process gets blocked on waiting for interaction with a user prompt.