send email to team responsibles, not to the person joining the team

src/teams/email.py

@@ -49,7 +49,7 @@ def send_new_membership_email(membership):
     return _send_email(
         text_template='emails/new_membership_email.txt',
         html_template='emails/new_membership_email.html',
-        recipient=membership.user.email,
+        recipient=[resp.email for resp in membership.team.responsible],
         formatdict=formatdict,
         subject='New membership request for {} at {}'.format(
             membership.team.name,

src/utils/email.py

@@ -15,13 +15,16 @@ def _send_email(
     attachment=None,
     attachment_filename=None
 ):
+    if not isinstance(recipient, list):
+        recipient = [recipient]
+
     try:
         # put the basic email together
         msg = EmailMultiAlternatives(
             subject,
             render_to_string(text_template, formatdict),
             sender,
-            [recipient],
+            recipient,
             [settings.ARCHIVE_EMAIL]
         )