Invalid JSON produced by apps:create

When using `atomic apps:create` the output includes this line at the end:

```
[apps:create] Time: 8.48 seconds, Memory: 6.00mb
```

This makes the output invalid JSON and cause `jq` to give an `invalid string literal` error when the output is passed as a variable like this:

```bash
app_json_object=$( atomic apps:create "$account_id" "$site_url" "$site_url" )

app_id=$( jq '.[ "id" ]' <<< "$app_json_object" )
```

I think that last line shouldn't be added to the output, perhaps only being added if a some kind of a debug flag is used.