message: bring back in other button options
diff: import React from 'react'
  import classnames from 'classnames'
  -function Button({is: Tag = 'button', children, grouped, scheme, ...props}) {
  - const className = ['btn']
  +function Button({is: Tag = 'button', children, size, block, linkStyle, grouped, scheme, ...props}) {
  + const className = [linkStyle ? 'btn-link' : 'btn']
  if (scheme) className.push(`btn-${scheme}`)
  if (grouped) className.push('BtnGroup-item')
  + if (size === "small") className.push('btn-sm')
  + if (size === "large") className.push('btn-large')
  + if (block) className.push('block')
  return (
  <Tag {...props} className={className.join(' ')}>{children}
  </Tag>
  