tests for add action item.
Merge branch 'master' of https://github.com/ccnmtl/dmt into action-item-enhancement

Conflicts:
	.gitignore
add delete item functionality. see PMT #93943

UI follows the same pattern as the old PMT. We want to discourage people from
deleting items, since that would throw away history.

So the "delete item" button is hidden off on the edit item page.
flake8'ing
Merge pull request #17 from sdreher/action-item-enhancement

Action item enhancement -- tests for ProjectAddItemView
Merge pull request #18 from thraxil/delete-item

Delete item