Fix plan count in api test.

There was an incorrect plan count in one of the tests. It's troubling that this did not cause a failure.

Issue filed in `tap` project:
  tapjs/tapjs#198

Author: jamestalmage

test/api.js

@@ -260,7 +260,7 @@ test('absolute paths', function (t) {
 });
 
 test('search directories recursivly for files', function (t) {
-	t.plan(1);
+	t.plan(2);
 
 	var api = new Api([path.join(__dirname, 'fixture/subdir')]);