Update test of text with position:absolute

The following code:

```
<span class="show-for-sr">You're on page</span> 1
```

Will generate an element with `position: absolute`. When reading the
contents, it's not clear whether this element is supposed to be in the
 same paragraph or in a different one. Currently Capybara treats it as
if it were part of a different paragraph.

Since this could be the way screen readers read the text, I'm changing
the test to reflect this fact. We might change our minds in the future.

spec/features/legislation/proposals_spec.rb

@@ -72,12 +72,12 @@ describe "Legislation Proposals" do
 
       click_link "Next"
 
-      expect(page).to have_content "You're on page 2"
+      expect(page).to have_content "You're on page\n2"
       expect(first_page_proposals_order & legislation_proposals_order).to eq([])
 
       click_link "Previous"
 
-      expect(page).to have_content "You're on page 1"
+      expect(page).to have_content "You're on page\n1"
       expect(legislation_proposals_order).to eq(first_page_proposals_order)
     end