More info in "not a legal parameter" error

Without this, I was getting:

```
ERROR: apt is not a legal parameter in an Ansible task or handler
```

which doesn't give me any idea what task ansible is having trouble with
(I reference "apt" many times in many roles)

With this, I get:

```
ERROR: apt is not a legal parameter in an Ansible task or handler
    task: {'sudo': True, 'name': 'Update apt-get cache', 'apt': 'update_cache=yes cache_valid_time=86400', 'tags': ['apt']}
    role_name: 'common'
```

which points me right at the task that ansible is having trouble with.