Decode the console log stream

For python 3 compatibility the console log stream must be
decoded. Otherwise zuul executor crashes with [1].

[1] Stack trace:
Ansible out b'Traceback (most recent call last):'
Ansible out b'  File "/usr/lib/python3.5/multiprocessing/process.py", line 249, in _bootstrap'
Ansible out b'    self.run()'
Ansible out b'  File "/usr/lib/python3.5/multiprocessing/process.py", line 93, in run'
Ansible out b'    self._target(*self._args, **self._kwargs)'
Ansible out b'  File "/mnt/zuul/state/ansible/callback/zuul_stream.py", line 98, in _read_log'
Ansible output: b'    for line in linesplit(s):'
Ansible output: b'  File "/mnt/zuul/state/ansible/callback/zuul_stream.py", line 30, in linesplit'
Ansible output: b'    if "\\n" in buff:'
Ansible output: b"TypeError: a bytes-like object is required, not 'str'"
Ansible output: b'Process Process-8:'
Ansible output: b'Traceback (most recent call last):'
Ansible output: b'  File "/usr/lib/python3.5/multiprocessing/process.py", line 249, in _bootstrap'
Ansible output: b'    self.run()'
Ansible output: b'  File "/usr/lib/python3.5/multiprocessing/process.py", line 93, in run'
Ansible output: b'    self._target(*self._args, **self._kwargs)'
Ansible output: b'  File "/mnt/zuul/state/ansible/callback/zuul_stream.py", line 98, in _read_log'
Ansible output: b'    for line in linesplit(s):'
Ansible output: b'  File "/mnt/zuul/state/ansible/callback/zuul_stream.py", line 30, in linesplit'
Ansible output: b'    if "\\n" in buff:'
Ansible output: b"TypeError: a bytes-like object is required, not 'str'"

Change-Id: Ia371562be3f30a5608e901349eda4cea77d7367d
diff --git a/zuul/ansible/callback/zuul_stream.py b/zuul/ansible/callback/zuul_stream.py
index fd95e92..904316c 100644
--- a/zuul/ansible/callback/zuul_stream.py
+++ b/zuul/ansible/callback/zuul_stream.py
@@ -24,14 +24,14 @@
 
 
 def linesplit(socket):
-    buff = socket.recv(4096)
+    buff = socket.recv(4096).decode("utf-8")
     buffering = True
     while buffering:
         if "\n" in buff:
             (line, buff) = buff.split("\n", 1)
             yield line + "\n"
         else:
-            more = socket.recv(4096)
+            more = socket.recv(4096).decode("utf-8")
             if not more:
                 buffering = False
             else: