Fix duplicated ‘GOV.UK Notify’ in page titles

The `per_page_title` block appends ‘– GOV.UK Notify’ – there’s no need
to hard code it (see e4b040b380/app/templates/admin_template.html (L15))

app/templates/error/400.html

@@ -1,5 +1,5 @@
 {% extends "withoutnav_template.html" %}
-{% block per_page_title %}Bad Request – GOV.UK Notify{% endblock %}
+{% block per_page_title %}Bad request{% endblock %}
 {% block maincolumn_content %}
 <div class="grid-row">
     <div class="column-two-thirds">

app/templates/error/401.html

@@ -1,5 +1,5 @@
 {% extends "withoutnav_template.html" %}
-{% block per_page_title %}You are not authorised to see this page – GOV.UK Notify{% endblock %}
+{% block per_page_title %}You are not authorised to see this page{% endblock %}
 {% block maincolumn_content %}
   <div class="grid-row">
     <div class="column-two-thirds">

app/templates/error/403.html

@@ -1,5 +1,5 @@
 {% extends "withoutnav_template.html" %}
-{% block per_page_title %}You are not allowed to see this page – GOV.UK Notify{% endblock %}
+{% block per_page_title %}You are not allowed to see this page{% endblock %}
 {% block maincolumn_content %}
     <div class="grid-row">
       <div class="column-two-thirds">

app/templates/error/404.html

@@ -1,5 +1,5 @@
 {% extends "withoutnav_template.html" %}
-{% block per_page_title %}Page not found – GOV.UK Notify{% endblock %}
+{% block per_page_title %}Page not found{% endblock %}
 {% block maincolumn_content %}
     <div class="grid-row">
       <div class="column-two-thirds">

app/templates/error/410.html

@@ -1,5 +1,5 @@
 {% extends "withoutnav_template.html" %}
-{% block per_page_title %}Page not found – GOV.UK Notify{% endblock %}
+{% block per_page_title %}Page not found{% endblock %}
 {% block maincolumn_content %}
     <div class="grid-row">
       <div class="column-two-thirds">

app/templates/error/413.html

@@ -1,5 +1,5 @@
 {% extends "withoutnav_template.html" %}
-{% block per_page_title %}File too big – GOV.UK Notify{% endblock %}
+{% block per_page_title %}File too big{% endblock %}
 {% block maincolumn_content %}
     <div class="grid-row">
       <div class="column-two-thirds">

app/templates/error/500.html

@@ -1,5 +1,5 @@
 {% extends "withoutnav_template.html" %}
-{% block per_page_title %}Sorry, there’s a problem with the service – GOV.UK Notify{% endblock %}
+{% block per_page_title %}Sorry, there’s a problem with the service{% endblock %}
 {% block maincolumn_content %}
   <div class="grid-row">
     <div class="column-two-thirds">

tests/app/main/test_errorhandlers.py

@@ -10,6 +10,7 @@ def test_bad_url_returns_page_not_found(client):
     assert response.status_code == 404
     page = BeautifulSoup(response.data.decode('utf-8'), 'html.parser')
     assert page.h1.string.strip() == 'Page not found'
+    assert page.title.string.strip() == 'Page not found – GOV.UK Notify'
 
 
 def test_load_service_before_request_handles_404(client_request, mocker):
@@ -38,6 +39,7 @@ def test_malformed_token_returns_page_not_found(logged_in_client, url):
     assert page.h1.string.strip() == 'Page not found'
     flash_banner = page.find('div', class_='banner-dangerous').string.strip()
     assert flash_banner == "There’s something wrong with the link you’ve used."
+    assert page.title.string.strip() == 'Page not found – GOV.UK Notify'
 
 
 def test_csrf_returns_400(logged_in_client, mocker):
@@ -50,6 +52,7 @@ def test_csrf_returns_400(logged_in_client, mocker):
     assert response.status_code == 400
     page = BeautifulSoup(response.data.decode('utf-8'), 'html.parser')
     assert page.h1.string.strip() == 'Something went wrong, please go back and try again.'
+    assert page.title.string.strip() == 'Bad request – GOV.UK Notify'
 
 
 def test_csrf_redirects_to_sign_in_page_if_not_signed_in(client, mocker):
@@ -68,3 +71,4 @@ def test_405_returns_something_went_wrong_page(client, mocker):
     assert response.status_code == 405
     page = BeautifulSoup(response.data.decode('utf-8'), 'html.parser')
     assert page.h1.string.strip() == 'Something went wrong, please go back and try again.'
+    assert page.title.string.strip() == 'Bad request – GOV.UK Notify'