change print to logger.debug

.travis.yml

@@ -3,8 +3,8 @@ python:
     - "2.5"
     - "2.6"
     - "2.7"
-    - "3.1"
     - "3.2"
+    - "3.3"
 
 install: 
     - pip install six

plumbum/paramiko_machine.py

@@ -9,6 +9,7 @@ def __nonzero__(self):
         def __getattr__(self, name):
             raise ImportError("No module named paramiko")
     paramiko = paramiko()
+
 import logging
 import six
 import errno
@@ -71,7 +72,7 @@ def communicate(self):
                     line = infile.readline()
                 except (ValueError, IOError):
                     line = None
-                print("!! %s", (repr(line),))
+                logger.debug("communicate: %r", line)
                 if not line:
                     infile.close()
                     infile = None