Update test coverage integration

[cnizzardini]

Looks like test coverage reporting has been disabled: https://app.codecov.io/github/lorenzo/audit-stash

Let's either get @lorenzo to resolve that or move that over to another account.

[dereuromark]

@lorenzo Maybe this should be moved to https://github.com/FriendsOfCake/ ?
Could be easier to maintain, as some things require more admin level access