Pass rest of the props down into Button component
Pass rest of the props down into Button component

This way, custom sidebar components can receive props like `apiEndpoint` or `imageTitle` when declared at `sideButtons` prop.

````
<Editor
	sideButtons={[
		{
			title: 'Image',
			component: CustomImageButton,
			apiEndpoint: `${API_ENDPOINT}/some/api`,
			imageName: "my-seo-friendly-title.jpeg"
		}
	]}
	ref="editor"
	editorState={editorState}
	onChange={this.onChange} />
````
brijeshb42/medium-draft,brijeshb42/medium-draft