Fixed failing unit tests due to str/bytes mismatch.
Changed "assert isinstance(...)" in hmac.py to raise proper TypeError.
diff --git a/Lib/test/test_pty.py b/Lib/test/test_pty.py
index e2058ab..58a3041 100644
--- a/Lib/test/test_pty.py
+++ b/Lib/test/test_pty.py
@@ -157,7 +157,8 @@
                     break
                 if not data:
                     break
-                sys.stdout.write(data.replace('\r\n', '\n').decode('ascii'))
+                sys.stdout.write(str(data.replace(b'\r\n', b'\n'),
+                                     encoding='ascii'))
 
             ##line = os.read(master_fd, 80)
             ##lines = line.replace('\r\n', '\n').split('\n')