Use the classes `icon-only`, `icon-left` and `icon-right` when including icons inside of buttons.

### Variants

```js
import { ButtonToolbar, Button, DownloadGlyph } from 'frontend-react-components';

<ButtonToolbar>
    <Button>Default</Button>
    <Button className="icon-left"><DownloadGlyph/>With Icon</Button>
    <Button className="icon-only"><DownloadGlyph/></Button>
    <Button variant="primary">Primary</Button>
    <Button variant="danger">Danger</Button>
    <Button variant="link">Link</Button>
</ButtonToolbar>
```
### Sizes

```js
import { ButtonToolbar, Button } from 'frontend-react-components';

<div>
  <ButtonToolbar>
    <Button size="lg">
      Large button
    </Button>
  </ButtonToolbar>
  <ButtonToolbar>
    <Button size="sm">
      Small button
    </Button>
  </ButtonToolbar>
</div>
```
### States

```jsx
import { ButtonToolbar, Button } from 'frontend-react-components';

<div>
  <ButtonToolbar>
    <Button>
      Default
    </Button>
    <Button active>
      Active
    </Button>
    <Button disabled>
    Disabled
    </Button>{' '}
  </ButtonToolbar>
</div>
```
### Block

```jsx
import { ButtonToolbar, Button } from 'frontend-react-components';

<Button block>
  Block level button
</Button>

```
### Upgrading
Upgrading from 2.x.x to 3.x.x

Changed props:

- `bsStyle` -> `variant`
- `bsSize` -> `size`
- `componentClass` -> `as`