message: add open prop to dropdown
diff: @@ -146,7 +146,10 @@ declare module '@primer/components' {
  export const StyledOcticon: React.FunctionComponent<StyledOcticonProps>
  - export interface DropdownProps extends CommonProps, Omit<React.HTMLAttributes<HTMLElement>, 'color'> {}
  + export interface DropdownProps extends CommonProps, Omit<React.HTMLAttributes<HTMLElement>, 'color'> {
  + open?: boolean,
  +
  + }
  export interface DropdownItem extends CommonProps, Omit<React.HTMLAttributes<HTMLLIElement>, 'color'> {}
  