Log Message:
py-virtualenv: updated to 16.6.0

v16.6.0:
Features
- Drop Jython support. Jython became slower and slower in the last few months \ 
and significantly holds back our
  CI and development. As there's very little user base for it decided to drop \ 
support for it. If there are Jython
  developers reach out to us to see how we can add back support.
- Upgrade embedded packages:
      * upgrade wheel from 0.33.1 to 0.33.4
      * upgrade pip from 19.1 to 19.1.1

v16.5.0:
Bugfixes
- Add tests covering prompt manipulation during activation/deactivation,
  and harmonize behavior of all supported shells
- Handle running virtualenv from within a virtual environment created
  using the stdlib venv module. Fixes 1339.

Features
- -p option accepts Python version in following formats now: X, X-ZZ, X.Y and \ 
X.Y-ZZ, where ZZ is 32 or 64. (Windows only)
- upgrade pip from 19.0.3 to 19.1
- upgrade setuptools from 40.8.0 to 41.0.1

v16.4.3:
Bugfixes
- Revert the symlink fix, causing debian packaging issues.

v16.4.1:
Bugfixes
- Fix license() builtin by copying the LICENSE file into the virtualenv

Features
- bump vendored pip to 19.0.3 and wheel to 0.33.1

v16.4.0:
Bugfixes
- fixes the scenario where the python base install is symlinked with relative \ 
symlinks
- Use importlib over imp in virtualenv.py for python >= 3.4
- Copy or link PyPy header files instead of include directory itself
- Allow virtualenv creation with older pip not having config command
  correspondingly disabling configuration related features (such as pip cert
  setting) in this case.

Features
- upgrade to pip 19.0.2 and setuptools 40.8.0