Revert "Force pip version to 7.1.2 in tox for py32 (support dropped for latter versions)"

This reverts commit 7b7165f.

Author: touilleMan

tox.ini

@@ -12,7 +12,6 @@ deps =
     mg28: PyMongo>=2.8,<3.0
     mg30: PyMongo>=3.0
     mgdev: https://github.com/mongodb/mongo-python-driver/tarball/master
-    py32: pip==7.1.2
 setenv =
     PYTHON_EGG_CACHE = {envdir}/python-eggs
 passenv = windir