Release please: No longer installable on Python 3 due to setuptools dropping build_py_2to3

[ztane]

The 0.8.1 in PyPI is no longer installable using latest setuptools because it silently fails to import build_py_2to3 which would fix the import inside slimit/__init__.py.

[sfmqrb]

@rspivak No plan to resolve this issue?

[ztane]

The easiest solution would be to release a new version that deprecates support for Python 2.7.