message: add classnames syntax back
diff: @@ -2,14 +2,20 @@ import React from 'react'
  import classnames from 'classnames'
  function Button({is: Tag = 'button', children, size, block, linkStyle, grouped, scheme, ...props}) {
  - const className = [linkStyle ? 'btn-link' : 'btn']
  - if (scheme) className.push(`btn-${scheme}`)
  - if (grouped) className.push('BtnGroup-item')
  - if (size === "small") className.push('btn-sm')
  - if (size === "large") className.push('btn-large')
  - if (block) className.push('block')
  + const classes = classnames(
  + {
  + 'btn': !linkStyle,
  + 'btn-link': linkStyle,
  + 'btn-small': size === 'small',
  + 'btn-large': size === 'large',
  + 'btn-block': block,
  + 'BtnGroup-item': grouped,
  + }
  + scheme ? `btn-${scheme}`
  + );
  +
  return (
  - <Tag {...props} className={className.join(' ')}>{children}
  + <Tag {...props} className={classes}>{children}
  </Tag>
  )
  }
  