Info command changed the way gpg keys are shown.

With pull request #696, the representation of a GPG key for a Product
via CLI has changed from

```python
{u'gpg': u'', u'gpg-key': u'', u'gpg-key-id': u''}
```

to

```python
{u'gpg': {u'gpg-key': u'', u'gpg-key-id': u''}}
```

I believe the changes included here are enough to cover this scenario.
Merge pull request #726 from omaciel/use-correct-gpg-key

Info command changed the way gpg keys are shown.