Please update pyenv formula: v0.4.0-20131116

The changes in this release are below.

Changes:

* python-build: Add new CPython releases; 2.6.9, 2.7.6 (#76)
* python-build: Add new CPython release candidates; 3.3.3-rc1, 3.3.3-rc2
* python-build: Add new PyPy releases; pypy-2.2, pypy-2.2-src (#77)
* python-build: Update default setuptools version (1.1.6 -> 1.3.2)
* python-build: Imported recent changes from ruby-build v20131030