missing dependency: setuptools

[FirefoxMetzger]

Both validators import pkg_resources which is part of setuptools, however it is not listed as explicit dependency in the setup.py.

I know this doesn't cause a problem for most people as one technically needs setuptools to install things using a setup.py. In my case I install the library in a specific directory (using the --target flag with pip) and then want to use it with a different (sand-boxed) python, which doesn't have setuptools. Consequentially I get

File "[...]\lib\swagger_spec_validator\validator12.py", line 20, in <module>
from pkg_resources import resource_filename
ImportError: No module named pkg_resources

Would it be worth it adding setuptools to the list of dependencies? As a second thought, setuptools is a big dependency. Is it necessary? (I don't know the code base)