tests/screentest/testcases.txt: add status
Add status lines for tests that don't expect 200.
Trust: Jonathan Amsterdam
Run-TryBot: Jonathan Amsterdam
@@ -149,11 +149,13 @@ capture fullscreen
capture fullscreen 540x1080
test error
+status 400
pathname /bad.package@v1.0-badversion
capture fullscreen
capture fullscreen 540x1080
test 404 with fetch button
+status 404
pathname /github.com/package/does/not/exist
capture fullscreen
capture fullscreen 540x1080
