Add Visual Genome
_The documentation is not available anymore as the PR was closed or merged._ Hum there seems to be some issues with tasks in test:
 - some tasks don't fit anything in `tasks.json`. Do I remove them in `task_categories`?
 - some tasks should exist, typically `visual-question-answering` (https://github.com/huggingface/datasets/blame/9f2ff14673cac1f1ad56d80221a793f5938b68c7/src/datasets/utils/resources/tasks.json#L195) yet the exception is failing on me. I'm guessing it's because my `master` is not up-to-date. However this means that the testing only tests my branch instead of the one merged with master?
 
 cc @mariosasko @lhoestq  > some tasks don't fit anything in tasks.json. Do I remove them in task_categories?

You can keep them, but add `other-` as a prefix to those tasks to make the CI ignore it

> some tasks should exist, typically visual-question-answering (https://github.com/huggingface/datasets/blame/9f2ff14673cac1f1ad56d80221a793f5938b68c7/src/datasets/utils/resources/tasks.json#L195) yet the exception is failing on me. I'm guessing it's because my master is not up-to-date. However this means that the testing only tests my branch instead of the one merged with master?

Feel free to merge upstream/master into your branch ;)

EDIT: actually I just noticed you've already done this, thanks ! After offline discussions: will keep that image essentially it's necessary as I have a mapping that creates a mapping between url and local path (images are downloaded via a zip file) and dummy data needs to store that dummy image. The issue is when I read an annotation, I get a url, compute the local path, and basically I assume the local path exists since I've extracted all the images ... This isn't true if dummy data doesn't have all the images, so instead I've added a script that "fixes" the dummy data after using the CLI, it essentially adds the dummy image in the zip corresponding to the url.