Show error if you try to send too many messages

https://www.pivotaltracker.com/story/show/117630691

There is a limit of 50 messages per day in trial mode. Right now, we
don’t tell you this, we just start failing your messages.

This commit adds an error message if you upload a CSV file that has too
many rows in it.

app/main/views/send.py

@@ -26,7 +26,7 @@ from app.main.uploader import (
     s3upload,
     s3download
 )
-from app import job_api_client, service_api_client, current_service, user_api_client
+from app import job_api_client, service_api_client, current_service, user_api_client, statistics_api_client
 from app.utils import user_has_permissions, get_errors_for_csv
 
 
@@ -204,6 +204,8 @@ def check_messages(service_id, template_type, upload_id):
         return redirect(url_for('main.choose_template', service_id=service_id, template_type=template_type))
 
     users = user_api_client.get_users_for_service(service_id=service_id)
+    statistics = statistics_api_client.get_statistics_for_service(service_id, limit_days=1)['data']
+    statistics = statistics[0] if statistics else {}
 
     contents = s3download(service_id, upload_id)
     if not contents:
@@ -252,7 +254,8 @@ def check_messages(service_id, template_type, upload_id):
         original_file_name=session['upload_data'].get('original_file_name'),
         send_button_text=get_send_button_text(template.template_type, session['upload_data']['notification_count']),
         upload_id=upload_id,
-        form=CsvUploadForm()
+        form=CsvUploadForm(),
+        statistics=statistics
     )