Remove <h2> tag around service name in nav

The heading structure of most pages is incorrect (`<h2>` followed by
`<h1>`). The `<h1>` indicates the main purpose of the page, the service
name (currently the first `<h2>`) doesn't need to be a heading.

tests/app/main/views/test_dashboard.py

@@ -105,7 +105,6 @@ def test_should_show_recent_templates_on_dashboard(
 
     page = BeautifulSoup(response.data.decode('utf-8'), 'html.parser')
     headers = [header.text.strip() for header in page.find_all('h2') + page.find_all('h1')]
-    assert 'Test Service' in headers
     assert 'In the last 7 days' in headers
 
     table_rows = page.find_all('tbody')[1].find_all('tr')

tests/app/main/views/test_service_settings.py

@@ -102,7 +102,7 @@ def test_show_restricted_service(
     response = logged_in_client.get(url_for('main.service_settings', service_id=service_one['id']))
     page = BeautifulSoup(response.data.decode('utf-8'), 'html.parser')
     assert page.find('h1').text == 'Settings'
-    assert page.find_all('h2')[1].text == 'Your service is in trial mode'
+    assert page.find_all('h2')[0].text == 'Your service is in trial mode'
 
 
 def test_switch_service_to_live(