refactor(dummy_app): remove unneeded tables
test(list): add test for sortable and correct similiar test

Add title column to employee to test for sortable title_with_name
Refactor tests which use have_selector without text: option because
it DOES NOTHING without this option, this test passes e.g. this test
always passes
expect(page).to have_selector("tbody tr:first", "Non-existing text")