Allow compressing es6
Allow compressing es6

k0kubun/github-ranking,k0kubun/githubranking,k0kubun/githubranking,k0kubun/github-ranking,k0kubun/githubranking,k0kubun/githubranking,k0kubun/github-ranking,k0kubun/github-ranking,k0kubun/githubranking,k0kubun/github-ranking