Update README.md

Update README.md

[Add] unit test for frontend

[Mod] change configuration of frontend for making functionnal unit test

[Add] mocha for unit test backend

[Fix] remove all warnings

[Mod] change display of create and update task + fix problem for update task

[Mod] change navbar and list of all todos

Update README.md

[Rm] remove comments from the code

[Mod] remove comments

Update README.md

[Mod] change route / to /get-todo

Update README.md

Delete README.md