Use lib imports in tests

The module resolver handles the aliasing. With this, shipping tests with
published versions might be possible.
diff --git a/packages/selector/test/index.mjs b/packages/selector/test/index.mjs
index a5a4245..4ab7ce3 100644
--- a/packages/selector/test/index.mjs
+++ b/packages/selector/test/index.mjs
@@ -1,4 +1,4 @@
-import * as selector from '../src';
+import * as selector from '../lib';
 
 describe('selector', () => {
   it('can be imported', () => {