Update setuptools to 20.2.2

https://pythonhosted.org/setuptools/history.html
https://bitbucket.org/pypa/setuptools/branches/compare/20.2.2%0D19.6

The release on PyPI isn't signed, though the MD5 of this archive matches
that on the PyPI package page:

$ md5sum setuptools-20.2.2.tar.gz
bf37191cb4c1472fb61e6f933d2006b1 *setuptools-20.2.2.tar.gz

CHANGELOG.md

@@ -12,7 +12,7 @@ Improved GDAL support.
 - The vendored GDAL library has been updated to 1.11.1.
 - GDAL bootstrapping now also installs the GEOS and Proj.4 libraries.
 
-Updated pip to 8.1.0.
+Updated pip to 8.1.0 and setuptools to 20.2.2.
 
 ## v77 (2016-02-10)
 

bin/compile

@@ -35,7 +35,7 @@ DEFAULT_PYTHON_VERSION="python-2.7.11"
 DEFAULT_PYTHON_STACK="cedar-14"
 PYTHON_EXE="/app/.heroku/python/bin/python"
 PIP_VERSION="8.1.0"
-SETUPTOOLS_VERSION="19.6"
+SETUPTOOLS_VERSION="20.2.2"
 
 # Common Problem Warnings
 export WARNINGS_LOG=$(mktemp)