Fix import to make api tests green again

Fix for the latest nightly-api results, specifically:

```
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/nose/loader.py", line 411, in loadTestsFromName
    addr.filename, addr.module)
  File "/usr/lib/python2.7/site-packages/nose/importer.py", line 47, in importFromPath
    return self.importFromDir(dir_path, fqname)
  File "/usr/lib/python2.7/site-packages/nose/importer.py", line 94, in importFromDir
    mod = load_module(part_fqname, fh, filename, desc)
  File "/home/jenkins/workspace/foreman-nightly-api/tests/api/test_org.py", line 12, in <module>
    from robottelo.common.records.fields import basic_positive
ImportError: cannot import name basic_positive
```