python_bindings does not have an install script

python_bindings compile but cannot be installed system-wide.

Here is a ([starting](http://bloerg.net/2012/11/10/cmake-and-distutils.html) [point](http://stackoverflow.com/questions/18360245/python-c-compiling-shared-library-with-cmake-and-installing-with-distutils)) for how to implement this feature.
