Traceback (most recent call last):

 "<frozen importlib._bootstrap>", line 890, in _find_specAttributeError: 'CppFinder' object has no attribute 'find_spec'
Traceback (most recent call last):


 "/home/travis/virtualenv/python3.5.2/bin/twine", line 7, in <module>

from twine.__main__ import main


 "/home/travis/virtualenv/python3.5.2/lib/python3.5/site-packages/twine/__main__.py", line 20, in <module>

from twine.cli import dispatch


 "/home/travis/virtualenv/python3.5.2/lib/python3.5/site-packages/twine/cli.py", line 23, in <module>

import requests_toolbelt


 "/home/travis/virtualenv/python3.5.2/lib/python3.5/site-packages/requests_toolbelt/__init__.py", line 12, in <module>

from .adapters import SSLAdapter, SourceAddressAdapter


 "/home/travis/virtualenv/python3.5.2/lib/python3.5/site-packages/requests_toolbelt/adapters/__init__.py", line 12, in <module>

from .ssl import SSLAdapter


 "/home/travis/virtualenv/python3.5.2/lib/python3.5/site-packages/requests_toolbelt/adapters/ssl.py", line 16, in <module>

from .._compat import poolmanager


 "/home/travis/virtualenv/python3.5.2/lib/python3.5/site-packages/requests_toolbelt/_compat.py", line 51, in <module>

from urllib3.contrib import appengine as gaecontrib
ImportError: No module named 'urllib3'
