Cop idea: like a `Capybara/FindElementValueEq` cop

[ydah]

original issue: rubocop/rubocop-rspec#1342 (comment)

# bad
expect(find('input').value).to eq('foobar')
# good
expect(page).to have_field(with: 'foobar')

[dmytro-savochkin]

I would LOVE this!
However I understand it might be pretty hard to implement, especially if not limiting to just .value -> have_field. It can be also .text -> have_content for example (and quite a few others?).