message: refactor(plugin): overflow
diff: import { StyliPlugin } from '@styli/types'
  -export const overFlowTypes = ['visible', 'hidden', 'scroll']
  -
  export function isOverFlowKey(key: string) {
  - return /^overflow[XY]?$/.test(key)
  + return /^overflow[XY]?$/i.test(key)
  }
  export function overFlowPropToStyle(prop: string, propValue: any): any {
  - return { [prop]: propValue }
  + if (prop === 'overflow') return { [prop]: propValue }
  + const key = prop.replace(/[a-z]$/, last => last.toUpperCase())
  + return { [key]: propValue }
  }
  export default (): StyliPlugin => {
  