Renaming in Grunt - also works to move a file to a directory related to file name

rename-in-gruntfile.js

```
files: [
  {
    expand: true,
    cwd: 'branding/',
    src: ['**/*.scss'],
    dest: 'branding/',
    ext: '.css',
    rename: function(dest, src) { return (dest + src).replace('scss', 'css'); }
  },
  {
    expand: true,
    cwd: 'scss',
    src: '*.scss',
    dest: 'css',
    ext: '.css'
  }
]
```

`rename` is the magic part here. It takes the destination and source names and lets you modify them.