[BUG] Running test command on empty folder does not give feedback

When running `guida test` on an empty folder should show a message explaing we expect
a `guida.json` or `elm.json` file:

```
% guida test
% echo $?
1
```

When running `elm-test` this is the output:

```
% elm-test
`elm-test` requires an elm.json up the directory tree, but none could be found! To make one: elm init
% echo $?
1
```

Both return `1` code.