stop rc from including minimist argv in the config

we are getting `_` added to the `jsfmt` config, example:

```javascript
var jsfmt = require("jsfmt");

console.dir(jsfmt.getConfig());
```

```bash
$ node example.js some test stuff
{ preset: 'default',
  indent: 
   { value: '  ',
     TopLevelFunctionBlock: 1 },
  ...
  _: [ 'some', 'test', 'stuff' ] }
```