message: build: target es2017 / node 8 for cjs files
diff: @@ -212,7 +212,9 @@ function genConfig(name) {
  cacheRoot: path.resolve(__dirname, '../', 'node_modules/.rts2_cache'),
  tsconfigOverride: {
  compilerOptions: {
  - target: opts.transpile === false ? 'esnext' : 'es5'
  + // if targeting browser, target es5
  + // if targeting node, es2017 means Node 8
  + target: opts.transpile === false ? 'es2017' : 'es5'
  },
  exclude: ['test', 'test-dts']
  }
  