Fix github driver tests for py3

Urllib needs bytes for POST data.

Change-Id: I5cab622c50dbc50892526416944f52a8cd4364a7
diff --git a/tests/base.py b/tests/base.py
index b668322..21a5892 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -840,7 +840,7 @@
         """Emulates sending the GitHub webhook event to the connection."""
         port = self.webapp.server.socket.getsockname()[1]
         name, data = event
-        payload = json.dumps(data)
+        payload = json.dumps(data).encode('utf8')
         headers = {'X-Github-Event': name}
         req = urllib.request.Request(
             'http://localhost:%s/connection/%s/payload'
diff --git a/zuul/driver/github/__init__.py b/zuul/driver/github/__init__.py
index 2d6829d..e59dc58 100644
--- a/zuul/driver/github/__init__.py
+++ b/zuul/driver/github/__init__.py
@@ -14,10 +14,10 @@
 
 from zuul.driver import Driver, ConnectionInterface, TriggerInterface
 from zuul.driver import SourceInterface
-import githubconnection
-import githubtrigger
-import githubsource
-import githubreporter
+from zuul.driver.github import githubconnection
+from zuul.driver.github import githubtrigger
+from zuul.driver.github import githubsource
+from zuul.driver.github import githubreporter
 
 
 class GithubDriver(Driver, ConnectionInterface, TriggerInterface,