zerver/lib/notifications.py: Fix string encoding/decoding.

Correctly encode and decode strings in convert_html_to_markdown.
It wasn't possible to use universal_newlines=True since
Popen.communicate doesn't encode/decode strings correctly on
python 2.

zerver/lib/notifications.py

@@ -508,11 +508,11 @@ def convert_html_to_markdown(html):
         except OSError:
             continue
 
-    markdown = p.communicate(input=html.encode("utf-8"))[0].strip()
+    markdown = p.communicate(input=html.encode('utf-8'))[0].decode('utf-8').strip()
     # We want images to get linked and inline previewed, but html2text will turn
     # them into links of the form `![](http://foo.com/image.png)`, which is
     # ugly. Run a regex over the resulting description, turning links of the
     # form `![](http://foo.com/image.png?12345)` into
     # `[image.png](http://foo.com/image.png)`.
-    return re.sub(r"!\[\]\((\S*)/(\S*)\?(\S*)\)",
-                  r"[\2](\1/\2)", markdown.decode('utf-8'))
+    return re.sub(u"!\\[\\]\\((\\S*)/(\\S*)\\?(\\S*)\\)",
+                  u"[\\2](\\1/\\2)", markdown)

zerver/tests/test_hooks.py

@@ -763,7 +763,6 @@ class FreshdeskHookTests(WebhookTestCase):
     STREAM_NAME = 'freshdesk'
     URL_TEMPLATE = u"/api/v1/external/freshdesk?stream={stream}"
 
-    @skip_py3
     def test_ticket_creation(self):
         # type: () -> None
         """
@@ -830,7 +829,6 @@ Priority: **High** => **Low**"""
         # type: () -> None
         self.note_change("public_note", "public")
 
-    @skip_py3
     def test_inline_image(self):
         # type: () -> None
         """
@@ -934,7 +932,6 @@ class PagerDutyHookTests(WebhookTestCase):
         expected_message = u':grinning: Incident [48219](https://dropbox.pagerduty.com/incidents/PJKGZF9) resolved\n\n>mp_error_block_down_critical\u2119\u01b4'
         self.send_and_test_stream_message('mp_fail', u"incident 48219", expected_message)
 
-    @skip_py3
     def test_bad_message(self):
         # type: () -> None
         expected_message = 'Unknown pagerduty message\n``` py\n{u\'type\': u\'incident.triggered\'}\n```'