Write some tests for ensuring correctness

[Cotel]

We should write some test for proving that the app keeps doing what it is supposed to do.

I would recommend to write UI tests for decoupling from the implementation as we are going to try several approaches.

These tests should include:

• Empty case shows if no there are no todos.
• Todos should be rendered if the list is not empty.
• A Todo should be marked as Done (struck through) if clicked when it is not completed and viceversa.
• A Todo should be removed if clicked on the delete icon.
• A Todo should be added to the list after creating it. (This is a complex test as it involves navigation, form filling and navigating back).