title: Issue getting pipenv to work on OSX
body: <p>I'm having some issue getting pipenv to work on OSX</p>
  
  <p>I'm not inside any virtual env at the moment. To make sure I have the latest version, I ran </p>
  
  <pre><code>$ sudo pip3 install pipenv --upgrade
  </code></pre>
  
  <p>And that completes susccessfully.</p>
  
  <p>When I just run <code>pipenv install --dev --three</code>, I get:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/usr/local/bin/pipenv", line 6, in &lt;module&gt;
      from pkg_resources import load_entry_point
    File "&lt;frozen importlib._bootstrap&gt;", line 971, in _find_and_load
    File "&lt;frozen importlib._bootstrap&gt;", line 955, in _find_and_load_unlocked
    File "&lt;frozen importlib._bootstrap&gt;", line 656, in _load_unlocked
    File "&lt;frozen importlib._bootstrap&gt;", line 626, in _load_backward_compatible
    File "/Users/frederikcreemers/.venvburrito/lib/python2.7/site-packages/setuptools-8.2-py2.7.egg/pkg_resources.py", line 1649, in &lt;module&gt;
  AttributeError: module 'importlib._bootstrap' has no attribute 'SourceFileLoader
  </code></pre>
  
  <p>I didn't recognize this <code>.venvburrito</code>, but looking it up, it's a system for managing virtual environments from virtualenv and virtualenvwrapper. I don't remember ever installing it, but maybe it was a dependency of something else I used.</p>
  
  <p>When I run the command with sudo:</p>
  
  <pre><code>$ sudo pipenv install --dev --three
  
  Virtualenv already exists!
  Removing existing virtualenv…
  Creating a virtualenv for this project…
  Using /usr/local/bin/python3 to create virtualenv…
  ⠋Running virtualenv with interpreter /usr/local/bin/python3
  Using base prefix '/usr/local/Cellar/python3/3.6.4_2/Frameworks/Python.framework/Versions/3.6'
  New python executable in /Users/frederikcreemers/.local/share/virtualenvs/appointment_tracker-KjOE-2Zx/bin/python3.6
  Also creating executable in /Users/frederikcreemers/.local/share/virtualenvs/appointment_tracker-KjOE-2Zx/bin/python
  Installing setuptools, pip, wheel...done.
  
  Virtualenv location: /Users/frederikcreemers/.local/share/virtualenvs/appointment_tracker-KjOE-2Zx
  Pipfile.lock not found, creating…
  Locking [dev-packages] dependencies…
  Locking [packages] dependencies…
  Warning: Your dependencies could not be resolved. You likely have a mismatch in your sub-dependencies.
    You can use $ pipenv install --skip-lock to bypass this mechanism, then run $ pipenv graph to inspect the situation.
  Could not find a version that matches pylint&lt;1.8,&gt;=1.0,&gt;=1.5.6,&gt;=1.8.2
  Tried: 0.15.2, 0.16.0, 0.18.0, 0.18.1, 0.19.0, 0.20.0, 0.21.0, 0.21.1, 0.21.2, 0.21.3, 0.22.0, 0.23.0, 0.24.0, 0.25.0, 0.25.1, 0.25.2, 0.26.0, 0.27.0, 0.28.0, 1.0.0, 1.1.0, 1.2.0, 1.2.1, 1.3.0, 1.3.1, 1.4.0, 1.4.0, 1.4.1, 1.4.1, 1.4.2, 1.4.2, 1.4.3, 1.4.3, 1.4.4, 1.4.4, 1.4.5, 1.4.5, 1.5.0, 1.5.0, 1.5.1, 1.5.1, 1.5.2, 1.5.2, 1.5.3, 1.5.3, 1.5.4, 1.5.4, 1.5.5, 1.5.5, 1.5.6, 1.5.6, 1.6.0, 1.6.0, 1.6.1, 1.6.1, 1.6.2, 1.6.2, 1.6.3, 1.6.3, 1.6.4, 1.6.4, 1.6.5, 1.6.5, 1.7.0, 1.7.0, 1.7.1, 1.7.1, 1.7.2, 1.7.2, 1.7.3, 1.7.3, 1.7.4, 1.7.4, 1.7.5, 1.7.5, 1.8.0, 1.8.0, 1.8.1, 1.8.1, 1.8.2, 1.8.2
  CRITICAL:pip.utils:Error [Errno 2] No such file or directory: '"/usr/local/opt/python3/bin/python3.6"': '"/usr/local/opt/python3/bin/python3.6"' while executing command python setup.py egg_info
  Traceback (most recent call last):
    File "/usr/local/bin/pipenv", line 11, in &lt;module&gt;
      load_entry_point('pipenv==9.0.3', 'console_scripts', 'pipenv')()
    File "/usr/local/lib/python3.6/site-packages/pipenv/vendor/click/core.py", line 722, in __call__
      return self.main(*args, **kwargs)
    File "/usr/local/lib/python3.6/site-packages/pipenv/vendor/click/core.py", line 697, in main
      rv = self.invoke(ctx)
    File "/usr/local/lib/python3.6/site-packages/pipenv/vendor/click/core.py", line 1066, in invoke
      return _process_result(sub_ctx.command.invoke(sub_ctx))
    File "/usr/local/lib/python3.6/site-packages/pipenv/vendor/click/core.py", line 895, in invoke
      return ctx.invoke(self.callback, **ctx.params)
    File "/usr/local/lib/python3.6/site-packages/pipenv/vendor/click/core.py", line 535, in invoke
      return callback(*args, **kwargs)
    File "/usr/local/lib/python3.6/site-packages/pipenv/cli.py", line 1865, in install
      do_init(dev=dev, allow_global=system, ignore_pipfile=ignore_pipfile, system=system, skip_lock=skip_lock, verbose=verbose, concurrent=concurrent, deploy=deploy, pre=pre)
    File "/usr/local/lib/python3.6/site-packages/pipenv/cli.py", line 1311, in do_init
      do_lock(system=system, pre=pre)
    File "/usr/local/lib/python3.6/site-packages/pipenv/cli.py", line 1102, in do_lock
      pre=pre
    File "/usr/local/lib/python3.6/site-packages/pipenv/utils.py", line 557, in resolve_deps
      resolved_tree = actually_resolve_reps(deps, index_lookup, markers_lookup, project, sources, verbose, clear, pre)
    File "/usr/local/lib/python3.6/site-packages/pipenv/utils.py", line 507, in actually_resolve_reps
      resolved_tree.update(resolver.resolve(max_rounds=PIPENV_MAX_ROUNDS))
    File "/usr/local/lib/python3.6/site-packages/pipenv/patched/piptools/resolver.py", line 102, in resolve
      has_changed, best_matches = self._resolve_one_round()
    File "/usr/local/lib/python3.6/site-packages/pipenv/patched/piptools/resolver.py", line 200, in _resolve_one_round
      for dep in self._iter_dependencies(best_match):
    File "/usr/local/lib/python3.6/site-packages/pipenv/patched/piptools/resolver.py", line 283, in _iter_dependencies
      for dependency in self.repository.get_dependencies(ireq):
    File "/usr/local/lib/python3.6/site-packages/pipenv/patched/piptools/repositories/pypi.py", line 153, in get_dependencies
      result = reqset._prepare_file(self.finder, ireq)
    File "/usr/local/lib/python3.6/site-packages/pipenv/patched/pip/req/req_set.py", line 639, in _prepare_file
      abstract_dist.prep_for_dist()
    File "/usr/local/lib/python3.6/site-packages/pipenv/patched/pip/req/req_set.py", line 134, in prep_for_dist
      self.req_to_install.run_egg_info()
    File "/usr/local/lib/python3.6/site-packages/pipenv/patched/pip/req/req_install.py", line 438, in run_egg_info
      command_desc='python setup.py egg_info')
    File "/usr/local/lib/python3.6/site-packages/pipenv/patched/pip/utils/__init__.py", line 667, in call_subprocess
      cwd=cwd, env=env)
    File "/usr/local/Cellar/python3/3.6.4_2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/subprocess.py", line 709, in __init__
      restore_signals, start_new_session)
    File "/usr/local/Cellar/python3/3.6.4_2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/subprocess.py", line 1344, in _execute_child
      raise child_exception_type(errno_num, err_msg, err_filename)
  FileNotFoundError: [Errno 2] No such file or directory: '"/usr/local/opt/python3/bin/python3.6"': '"/usr/local/opt/python3/bin/python3.6"'
  </code></pre>