title: tox how to provide trusted host in pip install?
body: <p>I created local pypi server, I added <code>indexserver</code> config in my <code>tox.ini</code> to point to my local pypi server.</p>
  
  <p>$ cat tox.ini</p>
  
  <pre><code>[tox]
  indexserver =
      default = https://localhost
      trusted_host = localhost
  
  envlist = py27
  skipdist = True
  
  [testenv]
  commands=
      flake8 MyLib
      py.test -l --cov=MyLib --cov-report term-missing --cov-report xml --no-cov-on-fail
  </code></pre>
  
  <p>When I run the <code>tox</code> command, its give ssl error.</p>
  
  <pre><code>$ tox -rv
  using tox.ini: /var/lib/jenkins/workspace/cicd-mylib/tox.ini
  using tox-0.0.0.dev0 from /usr/lib/python2.6/site-packages/tox/__init__.pyc
  GLOB sdist-make: /var/lib/jenkins/workspace/cicd-mylib/setup.py
    /var/lib/jenkins/workspace/cicd-mylib$ /usr/bin/python /var/lib/jenkins/workspace/cicd-mylib/setup.py sdist --formats=zip --dist-dir /var/lib/jenkins/workspace/cicd-mylib/.tox/dist &gt;/var/lib/jenkins/workspace/cicd-mylib/.tox/log/tox-0.log
  py27 recreate: /var/lib/jenkins/workspace/cicd-mylib/.tox/py27
    /var/lib/jenkins/workspace/cicd-mylib/.tox$ /usr/bin/python -m virtualenv --python /var/lib/jenkins/.pyenv/shims/python2.7 py27 &gt;/var/lib/jenkins/workspace/cicd-mylib/.tox/py27/log/py27-0.log
  py27 inst: /var/lib/jenkins/workspace/cicd-mylib/.tox/dist/MyLib-2.0.26.zip
    /var/lib/jenkins/workspace/cicd-mylib$ /var/lib/jenkins/workspace/cicd-mylib/.tox/py27/bin/pip install -i https://localhost /var/lib/jenkins/workspace/cicd-mylib/.tox/dist/MyLib-2.0.26.zip &gt;/var/lib/jenkins/workspace/cicd-mylib/.tox/py27/log/py27-1.log
  ERROR: invocation failed (exit code 1), logfile: /var/lib/jenkins/workspace/cicd-mylib/.tox/py27/log/py27-1.log
  ERROR: actionid: py27
  msg: installpkg
  cmdargs: ['/var/lib/jenkins/workspace/cicd-mylib/.tox/py27/bin/pip', 'install', '-i', 'https://localhost', '/var/lib/jenkins/workspace/cicd-mylib/.tox/dist/MyLib-2.0.26.zip']
  
  Processing ./.tox/dist/MyLib-2.0.26.zip
  Collecting cython (from MyLib==2.0.26)
    Could not fetch URL https://localhost/cython/: There was a problem confirming the ssl certificate: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:661) - skipping
    Could not find a version that satisfies the requirement cython (from MyLib==2.0.26) (from versions: )
  No matching distribution found for cython (from MyLib==2.0.26)
  
    /var/lib/jenkins/workspace/cicd-mylib$ /var/lib/jenkins/workspace/cicd-mylib/.tox/py27/bin/pip freeze &gt;/var/lib/jenkins/workspace/cicd-mylib/.tox/py27/log/py27-2.log
  py27 installed:
  _______________________________________________________________________________________________________________ summary _______________________________________________________________________________________________________________
  ERROR:   py27: InvocationError: /var/lib/jenkins/workspace/cicd-mylib/.tox/py27/bin/pip install -i https://localhost /var/lib/jenkins/workspace/cicd-mylib/.tox/dist/MyLib-2.0.26.zip (see /var/lib/jenkins/workspace/cicd-mylib/.tox/py27/log/py27-1.log)
  </code></pre>
  
  <p>When tox runs, its not passing <code>--trusted-host</code> variable in command <code>cmdargs: ['/var/lib/jenkins/workspace/cicd-mylib/.tox/py27/bin/pip', 'install', '-i', 'https://localhost', '/var/lib/jenkins/workspace/cicd-mylib/.tox/dist/MyLib-2.0.26.zip']</code></p>
  
  <p>How to pass that?</p>