fix(Segment): loading with clearing does not show the icon

[rkosafo]

Steps to Reproduce

1. Using the segment sample with loading
2. Add clearing

Expected
The Segment should show the loading icon

Result
The Segment does not show the loading icon

Testcase
If the docs show the issue, use: http://react.semantic-ui.com/elements/segment
Otherwise, fork this to get started: http://codepen.io/levithomason/pen/ZpBaJX

import React from 'react'
import { Image, Segment } from 'semantic-ui-react'

const SegmentExampleLoading = () => (
  <Segment loading clearing>
    <Image src='http://semantic-ui.com/images/wireframe/paragraph.png' />
  </Segment>
)

export default SegmentExampleLoading

[levithomason]

This seems sane to me, however, this is a CSS issue and this repo only deals with React components. The CSS for SUI is here: https://github.com/Semantic-Org/Semantic-UI.

A workaround is to manually place a loader within the Segment:

http://react.semantic-ui.com/elements/loader

import React from 'react'
import { Dimmer, Image, Loader, Segment } from 'semantic-ui-react'

const SegmentExampleLoading = () => (
  <Segment clearing>
    <Dimmer active inverted>
      <Loader inverted />
    </Dimmer>

    <Image src='http://semantic-ui.com/images/wireframe/paragraph.png' />
  </Segment>
)

export default SegmentExampleLoading