scandir doesn't behave like Python 3 version: lacks context manager

[oogali]

In Python 3.5, I can call scandir via a context manager where as under Python 2.7, I cannot.

Python 3.6.5 (v3.6.5:f59c0932b4, Mar 28 2018, 03:03:55)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from os import scandir
>>> with scandir('/etc') as d:
...   for entry in d:
...     print(entry.name)
...
emond.d
ntp-restrict.conf
periodic
manpaths
services~previous
dnsextd.conf
(and many more files)

Python 2.7.10 (default, Oct  6 2017, 22:29:07)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.31)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from scandir import scandir
>>> with scandir('/etc') as d:
...   for entry in d:
...     print entry.name
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: __exit__
>>>

[oogali]

And to clarify, here's a stack trace from a real program I'm having an issue with:

Traceback (most recent call last):
  File "/Users/oogali/.../venv/bin/forwarder", line 11, in <module>
    load_entry_point('forwarder', 'console_scripts', 'forwarder')()
  File "/Users/oogali/.../forwarder/forwarder/__main__.py", line 12, in main
    forwarder.run()
  File "/Users/oogali/.../forwarder/forwarder/forwarder.py", line 46, in run
    for spool_file in self.gather_files():
  File "/Users/oogali/.../forwarder/forwarder/forwarder.py", line 30, in gather_files
    with scandir(directory) as spool:
AttributeError: __exit__

[benhoyt]

Yes, you're right. This is a duplicate of #60 so I'll close this one -- basically none of the Python 3.6 additions have been back-ported to the scandir library. I don't have the time to incorporate these now (and it's becoming less and less important as Python 3.x takes over), but I'd welcome quality pull requests.