urlopen CERTIFICATE_VERIFY_FAILED error

gistfile1.txt

import TCIABrowserLib

c=TCIABrowserLib.TCIAClient(baseUrl='https://services.cancerimagingarchive.net/services/TCIA/TCIA/query')
c.get_collection_values()

gistfile2.txt

import TCIAClient

c=TCIAClient.TCIAClient(baseUrl='https://services.cancerimagingarchive.net/services/TCIA/TCIA/query')
c.get_collection_values()

Problem description

Running the test in gistfile1.py inside Slicer fails with the stack below, running the test in gistfile2.txt directly using either system python, or python-real from the same Slicer nightly does not fail. The reason for 2 separate tests is that TCIABrowserLib depends on vtk and such and cannot be run using stock python.

Traceback (most recent call last):
  File "<string>", line 7, in <module>
  File "test.py", line 5, in <module>
    c.get_collection_values()
  File "/Applications/Slicer-nightly/Slicer.app/Contents/Extensions-24649/TCIABrowser/lib/Slicer-4.4/qt-scripted-modules/TCIABrowserLib/TCIAClient.py", line 48, in get_collection_values
    resp = self.execute(serviceUrl , queryParameters)
  File "/Applications/Slicer-nightly/Slicer.app/Contents/Extensions-24649/TCIABrowser/lib/Slicer-4.4/qt-scripted-modules/TCIABrowserLib/TCIAClient.py", line 29, in execute
    resp = urllib2.urlopen(request)
  File "/Applications/Slicer-nightly/Slicer.app/Contents/lib/Python/lib/python2.7/urllib2.py", line 154, in urlopen
    return opener.open(url, data, timeout)
  File "/Applications/Slicer-nightly/Slicer.app/Contents/lib/Python/lib/python2.7/urllib2.py", line 431, in open
    response = self._open(req, data)
  File "/Applications/Slicer-nightly/Slicer.app/Contents/lib/Python/lib/python2.7/urllib2.py", line 449, in _open
    '_open', req)
  File "/Applications/Slicer-nightly/Slicer.app/Contents/lib/Python/lib/python2.7/urllib2.py", line 409, in _call_chain
    result = func(*args)
  File "/Applications/Slicer-nightly/Slicer.app/Contents/lib/Python/lib/python2.7/urllib2.py", line 1240, in https_open
    context=self._context)
  File "/Applications/Slicer-nightly/Slicer.app/Contents/lib/Python/lib/python2.7/urllib2.py", line 1197, in do_open
    raise URLError(err)
urllib2.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)>

Steps to reproduce

1. Clone this repository: https://github.com/QIICR/TCIABrowser
2. Run either test from TCIABrowser/TCIABrowser/TCIABrowserLib