Remove app/addon shadowing test

Author: dfreeman

tests/unit/build-test.ts

@@ -4,7 +4,6 @@ import addonFileA from 'in-repo-a/test-file';
 import addonFileB from 'in-repo-b/test-file';
 import fileA from 'dummy/a';
 import fileB from 'dummy/b';
-import shadowedFile from 'dummy/shadowed-file';
 import { description as fromAts } from 'in-repo-a/test-support/from-ats';
 import { description as fromTs } from 'dummy/tests/from-ts';
 
@@ -19,10 +18,6 @@ module('Unit | Build', function() {
     assert.equal(fileB, 'dummy/b');
   });
 
-  test('app files aren\'t shadowed by addons\' app tree files', function(assert) {
-    assert.equal(shadowedFile, 'dummy/shadowed-file');
-  });
-
   test('addon\'s addon-test-support files end up in <addon-name>/test-support/*', function (assert) {
     assert.ok(fromAts);
     assert.equal(fromAts, 'From addon-test-support');