Add tests for core logic

[kas-catholic]

It would be good to have some tests around the logic to add and remove items. These should be built in whatever framework is most commonly used by create-react-app.

[abhimaurya-dev]

I would like to work on adding tests. I am thinking about using Mocha framework. Do you have any recommendation of what framework i should be using ?

[kas-catholic]

We do already have some tests (written since this issue was created, I think). They can be run with yarn test. They're using Jest, so we should continue using that framework.

E.x.

confessit-web/src/AddButton.test.js

Lines 38 to 45 in ea1e2c0

	describe("handleClose", () => {
	it("should set showModal to false", () => {
	instance.state.showModal = true;
	instance.handleClose();
	expect(instance.state.showModal).toBe(false);
	});
	});