Failed unittest for packagedcode2/test_rubygems.py

## Information
- OS: Ubuntu 16.04
- Python: CPython 2.7.13
- Scancode-toolkit-contrib-version: 13495e3764721d6b110173688c258b45bcd47058
- Description: After I follow your contributing guide, and run for test, it occured failed messages for these reason.
```
> assert sorted(expected.items()) == sorted(results.items())
E AssertionError: assert [('authors', ...', None), ...] == [('authors', [...', None), ...]
E At index 22 diff: (u'licenses', []) != (u'installed_by_version', None)
E Right contains more items, first extra item: ('version', '0.1.3')
E Use -v to get the full diff
```