add test for asynchronously adding subtests

Author: grncdr

test/add-subtest-async.js

@@ -0,0 +1,11 @@
+var test = require('../')
+
+test('parent', function (t) {
+  t.pass('parent');
+  setTimeout(function () {
+    t.test('child', function (t) {
+      t.pass('child');
+      t.end();
+    });
+  }, 100)
+})