Vendor virtualenv, update to 15.1.0.

bootstrap/virtualenv/virtualenv-15.1.0.dist-info/DESCRIPTION.rst

+Virtualenv
+==========
+
+`Mailing list <http://groups.google.com/group/python-virtualenv>`_ |
+`Issues <https://github.com/pypa/virtualenv/issues>`_ |
+`Github <https://github.com/pypa/virtualenv>`_ |
+`PyPI <https://pypi.python.org/pypi/virtualenv/>`_ |
+User IRC: #pypa
+Dev IRC: #pypa-dev
+
+Introduction
+------------
+
+``virtualenv`` is a tool to create isolated Python environments.
+
+The basic problem being addressed is one of dependencies and versions,
+and indirectly permissions. Imagine you have an application that
+needs version 1 of LibFoo, but another application requires version
+2. How can you use both these applications?  If you install
+everything into ``/usr/lib/python2.7/site-packages`` (or whatever your
+platform's standard location is), it's easy to end up in a situation
+where you unintentionally upgrade an application that shouldn't be
+upgraded.
+
+Or more generally, what if you want to install an application *and
+leave it be*?  If an application works, any change in its libraries or
+the versions of those libraries can break the application.
+
+Also, what if you can't install packages into the global
+``site-packages`` directory?  For instance, on a shared host.
+
+In all these cases, ``virtualenv`` can help you. It creates an
+environment that has its own installation directories, that doesn't
+share libraries with other virtualenv environments (and optionally
+doesn't access the globally installed libraries either).
+
+.. comment: 
+
+Release History
+===============
+
+15.1.0 (2016-11-15)
+-------------------
+
+* Support Python 3.6.
+
+* Upgrade setuptools to 28.0.0.
+
+* Upgrade pip to 9.0.1.
+
+* Don't install pre-release versions of pip, setuptools, or wheel from PyPI.
+
+
+15.0.3 (2016-08-05)
+-------------------
+
+* Test for given python path actually being an executable *file*, #939
+
+* Only search for copy actual existing Tcl/Tk directories (PR #937)
+
+* Generically search for correct Tcl/Tk version (PR #926, PR #933)
+
+* Upgrade setuptools to 22.0.5
+
+`Full Changelog <https://virtualenv.pypa.io/en/latest/changes.html>`_.
+