Replace channels and volumes with volumes/channel

Now that we’re a more mature platform we don’t care so much about the
load that one service might put on our platform.

We do care about intended volumes for two reasons:
- modelling the benefits that services get from using Notify
- managing stocks of envelopes (while our letter volumes are small
  enough that they could be skewed by one new service)

Changing to the ‘how many per year’ question also has the benefit of
mapping directly to the data we store in the ‘beta partners’
spreadsheet.

app/templates/views/service-settings/submit-request-to-go-live.html

@@ -13,27 +13,24 @@
 
       <h1 class="heading-large">Request to go live</h1>
 
-      <p class="bottom-gutter">
-        Tell us how you plan to use Notify. When we receive your request we’ll make your service live within one working day.
-      </p>
+      <div class="grid-row bottom-gutter-1-3">
+        <div class="column-five-sixths">
+          <p>
+            Tell us how you plan to use Notify. When we receive your request we’ll make your service live within one working day.
+          </p>
+        </div>
+      </div>
 
-      <form method="post" class="top-gutter">
-        {{ checkbox_group('What kind of messages will you be sending?', [
-          form.channel_email,
-          form.channel_sms,
-          form.channel_letter
-        ]) }}
+      <form method="post">
         <div class="form-group">
-          {{ textbox(form.start_date, width='1-1') }}
-          {{ textbox(form.start_volume, width='1-1', hint='For example, ‘1,000 per month’.') }}
-          {{ textbox(form.peak_volume, width='1-1', hint='For example, ‘Messages will increase to 20,000 per month in January’.') }}
+          {{ textbox(form.volume_email, width='1-2', hint='For example, 1,000,000') }}
+          {{ textbox(form.volume_sms, width='1-2', hint='For example, 500,000') }}
+          {{ textbox(form.volume_letter, width='1-2', hint='For example, 5,000') }}
         </div>
         <p class="bottom-gutter">
           By requesting to go live you’re agreeing to our <a href="{{ url_for('.terms') }}">terms of use</a>.
         </p>
-
         {{ page_footer('Request to go live') }}
       </form>
 
-
 {% endblock %}