Reword the add service page

Without the preview service name we probably have to go back to communicating
a bit more on the add service page. This commit brings back the two bullet
points about where the service name will appear, and tries to tie it into the
nice words that Matt Sheret wrote for us.

app/main/forms.py

@@ -164,13 +164,13 @@ class AddServiceForm(Form):
     name = StringField(
         'Service name',
         validators=[
-            DataRequired(message='Service name can not be empty')
+            DataRequired(message='Service name can’t be empty')
         ]
     )
 
     def validate_name(self, a):
         if a.data in self._names_func():
-            raise ValidationError('Service name already exists')
+            raise ValidationError('This service name is already in use')
 
 
 class ServiceNameForm(Form):

app/templates/views/add-service.html

@@ -16,16 +16,29 @@
     </h1>
 
     <p>
-      Be specific. Remember that there might be other people in your
-      organisation using GOV.UK Notify.
+      Be specific to your service. Remember that there might be
+      other people in your organisation using GOV.UK Notify.
     </p>
 
+    <p>
+      Users will see this:
+    </p>
+
+    <ul class="list-bullet bottom-gutter">
+      <li>
+        at the start of every text message, eg ‘Vehicle tax: we received your
+        payment, thank you’
+      </li>
+      <li>
+        as your email sender name
+      </li>
+    </ul>
+
     <form autocomplete="off" method="post">
 
       {{ textbox(form.name, hint="You can change this later") }}
 
-
-      {{ page_footer('Continue') }}
+      {{ page_footer('Add service') }}
 
     </form>
 

tests/app/main/test_add_service_form.py

@@ -9,4 +9,4 @@ def test_form_should_have_errors_when_duplicate_service_is_added(app_):
         form = AddServiceForm(_get_form_names,
                               formdata=MultiDict([('name', 'some service')]))
         form.validate()
-        assert {'name': ['Service name already exists']} == form.errors
+        assert {'name': ['This service name is already in use']} == form.errors

tests/app/main/views/test_add_service.py

@@ -47,7 +47,7 @@ def test_should_return_form_errors_when_service_name_is_empty(app_,
             client.login(api_user_active)
             response = client.post(url_for('main.add_service'), data={})
             assert response.status_code == 200
-            assert 'Service name can not be empty' in response.get_data(as_text=True)
+            assert 'Service name can’t be empty' in response.get_data(as_text=True)
 
 
 def test_should_return_form_errors_with_duplicate_service_name(app_,
@@ -62,5 +62,5 @@ def test_should_return_form_errors_with_duplicate_service_name(app_,
             response = client.post(
                 url_for('main.add_service'), data={'name': 'service_one'})
             assert response.status_code == 200
-            assert 'Service name already exists' in response.get_data(as_text=True)
+            assert 'This service name is already in use' in response.get_data(as_text=True)
             assert mock_get_services.called