Package main was pointing to incorrect file

At some point, a switch was made to `coffee` and the files moved from `lib` to `src`, but the package `main` property was not updated accordingly. This fixes this problem. This was causing issues where other packages trying to run the `aglio` command would fail with the following error:

```
Loading "aglio.js" tasks...ERROR
>> Error: Cannot find module 'aglio'
```