Fix #6 Now you can also return value from define function like can be done with require.js

For example

    define(function(require, exports, module){

        var logic = {
            a: 3
        }
        return logic;
    });

will now work.

But this will continue to work too

    define(function(require, exports, module){

        var logic = {
            a: 3
        }
        exports.a= logic.a;
    });
``` js
var orignalExports = parent.exports;
var fnReturnExports = fn(reqFn, parent.exports, parent);
if(orignalExports === parent.exports && Object.keys(orignalExports).length === 0 && fnReturnExports !== undefined) {
  parent.exports = fnReturnExports;
}
```