Use venv for all builds and install everything from wheelhouse
Use venv and all minimum requirements
Edit requirements.txt in place and use one call
Update minimum versions and install exclusively from wheelhouse
Use mpl 1.3.1 on py 3.2
Fix pip invocation
Fix pip invocation again
Another fix to pip invocation
Explicitly use venv python to call build_versions.py
Move venv creation and activation to top level
Do not use site-packages
Fix minimum matplotlib ver and Pillow version check
Fix minimum matplotlib ver
Improve error message on version check
Add more debug info
Even more debug info
More debug info
Yet another debug print
Fix python 2.7 installation problem
check for PIL.Image version on install
Add debug to before_install
Try a pip install virtualenv first
Clean up virtualenv creation, add debug info, fix PySide script install
Fix virtualenv path for PySide install
Fix venv location and activation
Try no site packages and fix python 2.7 install