Use module.exports instead of exports

[jadonk]

From @adityapatadia on May 2, 2014 18:6

According to the documentation, we should use module.exports in bonescript and should avoid exports use. http://nodejs.org/api/modules.html#modules_exports_alias What are your thoughts?

Copied from original issue: jadonk#82

[jadonk]

Agreed, this is something good to fix.