pkgin.latest_version should throw keyerror
pkgin.latest_version should throw keyerror

```
KeyError: 'sabnzbd'
Traceback (most recent call last):
  File "/opt/local/bin/salt-call", line 11, in <module>
    salt_call()
  File "/opt/local/lib/python2.7/site-packages/salt/scripts.py", line 391, in salt_call
    client.run()
  File "/opt/local/lib/python2.7/site-packages/salt/cli/call.py", line 58, in run
    caller.run()
  File "/opt/local/lib/python2.7/site-packages/salt/cli/caller.py", line 134, in run
    ret = self.call()
  File "/opt/local/lib/python2.7/site-packages/salt/cli/caller.py", line 204, in call
    ret['return'] = func(*args, **kwargs)
  File "/opt/local/lib/python2.7/site-packages/salt/modules/pkgin.py", line 190, in latest_version
    return pkglist[names[0]]
KeyError: 'sabnzbd'
Traceback (most recent call last):
  File "/opt/local/bin/salt-call", line 11, in <module>
    salt_call()
  File "/opt/local/lib/python2.7/site-packages/salt/scripts.py", line 391, in salt_call
    client.run()
  File "/opt/local/lib/python2.7/site-packages/salt/cli/call.py", line 58, in run
    caller.run()
  File "/opt/local/lib/python2.7/site-packages/salt/cli/caller.py", line 134, in run
    ret = self.call()
  File "/opt/local/lib/python2.7/site-packages/salt/cli/caller.py", line 204, in call
    ret['return'] = func(*args, **kwargs)
  File "/opt/local/lib/python2.7/site-packages/salt/modules/pkgin.py", line 190, in latest_version
    return pkglist[names[0]]
KeyError: 'sabnzbd'
```

We fix this by checking if we actually have an entry for names[0] before trying to return.

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt