Use generator syntax to support decorator

[kjanoudi]

This allows us to use a decorator when connecting the component, as is typically standard in higher order components for ES6. http://asaf.github.io/blog/2015/06/23/extending-behavior-of-react-components-by-es6-decorators/

We're now able to do this:

import Sortable from 'react-sortablejs'

@connect(
    (state) => ({
        ...state.myItems
    })
)
@Sortable({
    ref: 'list',
    model: 'myItems'
})
export default class RestaurantInventoryItems extends React.Component {

...
}

[cheton]

It looks awesome! Thanks for sharing this.