Fixed DDT issue with attributes decorator.

By adding a ``@attrib`` decorator before a ``@ddt`` decorator, we were
getting an exception being raised:

```bash
2014-03-23 16:04:52 - robottelo - DEBUG - Running test TestSubnet/test_update_success_ddt_7___vlanid____1__
2014-03-23 16:04:52 - robottelo - DEBUG - >>> LANG=en_US hammer -v -u admin -p changeme  --output csv subnet update --name='subnet-192168100' --vlanid='1'
2014-03-23 16:04:54 - robottelo - DEBUG - <<< [u'Message,Id,Name', u'Subnet updated,57,subnet-192168100', u'']
.E
======================================================================
ERROR: Dynamically updates the test name for DDT tests
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
TypeError: fix_test_name() takes exactly 1 argument (0 given)

----------------------------------------------------------------------
```

Changing the order fixed the false failure:

```bash
$ nosetests -c robottelo.properties tests/cli/test_subnet.py

----------------------------------------------------------------------
Ran 11 tests in 38.227s

OK
```