Added peridoic email sender with Celery

src/series/templates/new_episodes_verification.html

@@ -0,0 +1,9 @@
+{% autoescape off %}  
+
+Hi {{ user.username }},  
+There are new episodes of the series you recorded.
+{% for s, d in data %}
+{{d.count}} episodes of {{s.title}} you haven't watched (watched episode: {{s.last_season}} - {{s.last_episode}}).
+{% endfor %}
+
+{% endautoescape %}