tests in duration recipe throws adr errors

[AutomatedTester]

I tried to run the tests_in_duration recipe and the following happened.

(data) davidburns in ~/development/active-data-recipes(ruby-2.6.0) on master λ adr tests_in_duration
Traceback (most recent call last):
  File "/Users/davidburns/.virtualenvs/data/bin/adr", line 10, in <module>
    sys.exit(main())
  File "/Users/davidburns/.virtualenvs/data/lib/python3.7/site-packages/adr/cli.py", line 227, in main
    result = handler(remainder)
  File "/Users/davidburns/.virtualenvs/data/lib/python3.7/site-packages/adr/cli.py", line 180, in handle_recipe
    data = run_recipe(config.recipe, remainder)
  File "/Users/davidburns/.virtualenvs/data/lib/python3.7/site-packages/adr/recipe.py", line 84, in run_recipe
    parser = RequestParser(recipe_context_def, prog="adr {}".format(recipe), description=doc)
  File "/Users/davidburns/.virtualenvs/data/lib/python3.7/site-packages/adr/context.py", line 46, in __init__
    definition.setdefault("dest", name)
AttributeError: 'list' object has no attribute 'setdefault'