Add isatty() to ColoredStream

Some versions of pip expect sys.stdout to implement isatty().

This change prevents: "AttributeError: 'ColoredStream' object has no attribute 'isatty'"

Author: james-emerton

awslambda/deploy.py

@@ -34,7 +34,10 @@ def write(self, msg):
 
     def flush(self):
         self.__s.flush()
-
+        
+    def isatty(self):
+        return self.__s.isatty()
+    
 
 @contextmanager
 def do_thing(name):