Remove dist path from published package

[unix]

1. When the user needs to import a single icon:

// better
import Activity from '@zeit-ui/react-icons/activity'

// now
import Activity from '@zeit-ui/react-icons/dist/activity'

2. When import all icons, we also need to change the default export name:

// better
import { HomeIcon } from '@zeit-ui/react-icons'

// now
import { Home } from '@zeit-ui/react-icons'

It doesn't look good to add suffixes here, however, use import { Home as HomeIcon } grammar is more annoying. In many projects using material-ui, you can often see a lot of code similar to Home as HomeIcon.

[unix]

However, the style of HomeIcon seems a little cumbersome.