Define long() in Python 3

[cclauss]

long() was remove in Python 3 in favor of int().

[coveralls]

Coverage decreased (-0.02%) to 91.685% when pulling ffd265b on cclauss:patch-5 into effc2e5 on google:master.

[tvalentyn]

This change LGTM.
@kevinli7 could you help review / merge this?

[kevinli7]

I would prefer this:

import six
if six.PY3:
long = int

or

import sys
if sys.version > (3,):
long = int

[tvalentyn]

I don't have a strong opinion, but FYI feature detection is also acceptable and recommended in https://docs.python.org/3/howto/pyporting.html#use-feature-detection-instead-of-version-detection

[kevinli7]

Thanks for the reference. That's fine then.

[kevinli7]

Thanks for the reference. That's fine then.