Support merge_language option.

Closes #84.

djrill/mail/backends/djrill.py

@@ -194,6 +194,7 @@ class DjrillBackend(BaseEmailBackend):
             'track_opens', 'track_clicks', 'auto_text', 'auto_html',
             'inline_css', 'url_strip_qs',
             'tracking_domain', 'signing_domain', 'return_path_domain',
+            'merge_language',
             'tags', 'preserve_recipients', 'view_content_link', 'subaccount',
             'google_analytics_domains', 'google_analytics_campaign',
             'metadata']

djrill/tests/test_mandrill_send.py

@@ -343,6 +343,7 @@ class DjrillMandrillFeatureTests(DjrillBackendMockAPITestCase):
     def test_merge(self):
         # Djrill expands simple python dicts into the more-verbose name/content
         # structures the Mandrill API uses
+        self.message.merge_language = "mailchimp"
         self.message.global_merge_vars = { 'GREETING': "Hello",
                                            'ACCOUNT_TYPE': "Basic" }
         self.message.merge_vars = {
@@ -352,6 +353,7 @@ class DjrillMandrillFeatureTests(DjrillBackendMockAPITestCase):
             }
         self.message.send()
         data = self.get_api_call_data()
+        self.assertEqual(data['message']['merge_language'], "mailchimp")
         self.assertEqual(data['message']['global_merge_vars'],
             [ {'name': 'ACCOUNT_TYPE', 'content': "Basic"},
               {'name': "GREETING", 'content': "Hello"} ])
@@ -456,6 +458,7 @@ class DjrillMandrillFeatureTests(DjrillBackendMockAPITestCase):
         self.assertFalse('google_analytics_domains' in data['message'])
         self.assertFalse('google_analytics_campaign' in data['message'])
         self.assertFalse('metadata' in data['message'])
+        self.assertFalse('merge_language' in data['message'])
         self.assertFalse('global_merge_vars' in data['message'])
         self.assertFalse('merge_vars' in data['message'])
         self.assertFalse('recipient_metadata' in data['message'])

djrill/tests/test_mandrill_send_template.py

@@ -48,7 +48,6 @@ class DjrillMandrillSendTemplateTests(DjrillBackendMockAPITestCase):
         msg.use_template_from = True
         with self.assertRaises(MandrillAPIError):
             msg.send()
-            self.assertEqual(sent, 0)
 
     def test_send_template_without_subject_field(self):
         msg = mail.EmailMessage('Subject', 'Text Body',