move QUnit assets into test-vendor.js and test-vendor.css. Add type option to import to specify which that it's a test asset
remove deprecation warning
use _processedVendorTree() instead of hardcoded 'vendor'
add change log entry. Use populateLegacyFiles to populate test files
Merge pull request #1288 from jakecraige/test-vendor-assets

Test assets moved to test-vendor.js and test-vendor.css.