Remove all empty translations

Some of the challenges in the seed files have translations with no text. These will cause errors when campers have selected these languages. These look like:

      "translations": {
        "de": {
          "description": [],
          "title": ""
        }
      }

In this case, we would need to delete

        "de": {
          "description": [],
          "title": ""
        }

We need to go through and delete all of these empty translations from seed files, and leave the empty "translation": {}

[raisedadead]

@envy7 you can do it in anyway as it suits you, but make sure when you have opened the pull request it has one commit.

Also, refer the contributing guide, most things have been answered there to guide you!

Thanks and happy fixing!

[envy7]

@QuincyLarson there are a lot of seed files should I do all the changes in a single commit, or in multiple commits and then squash them? Does it make a difference?