Remove Python 2 handling of string encoding

catkin_tools/execution/io.py

@@ -26,19 +26,6 @@
 
 MAX_LOGFILE_HISTORY = 10
 
-if type(u'') == str:
-    def _encode(string):
-        """Encode a Python 3 str into bytes.
-        :type data: str
-        """
-        return string.encode('utf-8')
-else:
-    def _encode(string):
-        """Encode a Python 2 str into bytes.
-        :type data: str
-        """
-        return string.decode('utf-8').encode('utf-8')
-
 
 class IOBufferContainer(object):
 
@@ -133,7 +120,7 @@ def _encode(data):
         """Encode a Python str into bytes.
         :type data: str
         """
-        return _encode(data)
+        return data.encode('utf8')
 
     @staticmethod
     def _decode(data):