Fix for Profile Options not Fully Merging

When setting up custom profile.yaml files for my projects, I found that the options I was setting for pylint weren't being respected. After some digging, I found that the merging functionality didn't seem to do what it needed to do in order to carry my options over.

The tests around profiles and merging still pass (after modifying one due to removing some functionality in _merge_dict), and my custom profiles are now working as expected. But, you may want to poke at this a bit more to see if I missed something.