message: use <FlexContainer>
diff: @@ -28,7 +28,7 @@ const MergeButton = ({numCommits, onClick, primary}) => {
  const commits = numCommits === 1 ? '1 commit' : `${numCommits} commits`
  return (
  - <div className="BtnGroup d-flex">
  + <FlexContainer className="BtnGroup">
  <Button {...buttonSchemeProps} grouped onClick={onClick} css={{borderRight: 0}}>
  Merge Pull Request
  </Button>
  @@ -71,7 +71,7 @@ const MergeButton = ({numCommits, onClick, primary}) => {
  </React.Fragment>
  )}
  </Details>
  - </div>
  + </FlexContainer>
  )
  }
  