Merge pull request #7 from dbaxa/python_3_support

More Python 3 support changes.

Author: Byron

smmap/test/lib.py

@@ -22,7 +22,7 @@ def __init__(self, size, prefix=''):
 
         fp = open(self._path, "wb")
         fp.seek(size-1)
-        fp.write('1')
+        fp.write(b'1')
         fp.close()
 
         assert os.path.getsize(self.path) == size

smmap/util.py

@@ -104,7 +104,7 @@ class MapRegion(object):
                     '_size', # cached size of our memory map
                     '__weakref__'
                 ]
-    _need_compat_layer = sys.version_info[1] < 6
+    _need_compat_layer = sys.version_info[0] < 3 and sys.version_info[1] < 6
 
     if _need_compat_layer:
         __slots__.append('_mfb')        # mapped memory buffer to provide offset