Fix __str__ method on the TimeoutExpired exception class. Also fix argument

order in the class constructor so it uses the same order as the actual class
from Python 3.3 and above.

TimeoutExpired from Python 3.3 takes arguments in the following order:
cmd, timeout, output.

See https://github.com/python/cpython/blob/master/Lib/subprocess.py#L388

eventlet/green/subprocess.py

@@ -21,8 +21,9 @@ if getattr(subprocess_orig, 'TimeoutExpired', None) is None:
         a child process.
         """
 
-        def __init__(self, timeout, cmd, output=None):
+        def __init__(self, cmd, timeout, output=None):
             self.cmd = cmd
+            self.timeout = timeout
             self.output = output
 
         def __str__(self):

tests/subprocess_test.py

@@ -12,13 +12,16 @@ def test_subprocess_wait():
     # In Python 3.3 subprocess.Popen.wait() method acquired `timeout`
     # argument.
     # RHEL backported it to their Python 2.6 package.
-    p = subprocess.Popen(
-        [sys.executable, "-c", "import time; time.sleep(0.5)"])
+    cmd = [sys.executable, "-c", "import time; time.sleep(0.5)"]
+    p = subprocess.Popen(cmd)
     ok = False
     t1 = time.time()
     try:
         p.wait(timeout=0.1)
-    except subprocess.TimeoutExpired:
+    except subprocess.TimeoutExpired as e:
+        str(e)  # make sure it doesnt throw
+        assert e.cmd == cmd
+        assert e.timeout == 0.1
         ok = True
     tdiff = time.time() - t1
     assert ok, 'did not raise subprocess.TimeoutExpired'