Fix build against the swarm cluster by joining buffered output before parsing json.

Signed-off-by: Daniel Nephin <dnephin@docker.com>

tests/integration/testcases.py

@@ -9,6 +9,8 @@ from compose.config.config import ServiceLoader
 from compose.const import LABEL_PROJECT
 from compose.progress_stream import stream_output
 from compose.service import Service
+from compose.utils import split_buffer
+from compose.utils import stream_as_text
 
 
 def pull_busybox(client):
@@ -71,5 +73,5 @@ class DockerClientTestCase(unittest.TestCase):
 
     def check_build(self, *args, **kwargs):
         kwargs.setdefault('rm', True)
-        build_output = self.client.build(*args, **kwargs)
-        stream_output(build_output, open('/dev/null', 'w'))
+        build_output = stream_as_text(self.client.build(*args, **kwargs))
+        stream_output(split_buffer(build_output), open('/dev/null', 'w'))

tests/unit/split_buffer_test.py

@@ -2,7 +2,7 @@ from __future__ import absolute_import
 from __future__ import unicode_literals
 
 from .. import unittest
-from compose.cli.utils import split_buffer
+from compose.utils import split_buffer
 
 
 class SplitBufferTest(unittest.TestCase):