Function iterator

test/internals/hook-runner.test.js:13–15

(fn, a, b, done)

  hookRunner([fn1, fn2, fn3], 'a', 'b', done)

  function iterator (fn, a, b, done) {
    return fn(a, b, done)
  }

  function fn1 (a, b, done) {
    t.assert.strictEqual(a, 'a')