applied isatty fix thanks to @piotrbartman to fix #254

Author: wolph

progressbar/utils.py

@@ -191,6 +191,9 @@ def __init__(self, target, capturing=False, listeners=set()):
         self.listeners = listeners
         self.needs_clear = False
 
+    def isatty(self):
+        return self.target.isatty()
+
     def write(self, value):
         if self.capturing:
             self.buffer.write(value)