Doesn't import under Python 3

[OddBloke]

Python 3.5.3+ (default, Jun  7 2017, 23:23:48) 
[GCC 6.3.0 20170519] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import treecompare
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/daniel/.virtualenvs/mypy/lib/python3.5/site-packages/treecompare/__init__.py", line 24, in <module>
    from .differ import make_differ
  File "/home/daniel/.virtualenvs/mypy/lib/python3.5/site-packages/treecompare/differ.py", line 1, in <module>
    from . import implementations as impl
  File "/home/daniel/.virtualenvs/mypy/lib/python3.5/site-packages/treecompare/implementations.py", line 98, in <module>
    class DiffNumbers(DiffPrimitives):
  File "/home/daniel/.virtualenvs/mypy/lib/python3.5/site-packages/treecompare/implementations.py", line 99, in DiffNumbers
    diffs_types = (int, long, float)
NameError: name 'long' is not defined