Fix unclosed file handles in setup.py.

TODO.rst

@@ -1,4 +0,0 @@
-TODO
-====
-
-* Switch to proper test skips once Django 1.3 is minimum supported.

setup.py

@@ -1,21 +1,29 @@
-from os.path import join
+import os
 from setuptools import setup, find_packages
 
 
-long_description = (open('README.rst').read() +
-                    open('CHANGES.rst').read() +
-                    open('TODO.rst').read())
+def long_desc(root_path):
+    FILES = ['README.rst', 'CHANGES.rst']
+    for filename in FILES:
+        filepath = os.path.realpath(os.path.join(root_path, filename))
+        if os.path.isfile(filepath):
+            with open(filepath, mode='r') as f:
+                yield f.read()
 
 
-def get_version():
-    with open(join('model_utils', '__init__.py')) as f:
+HERE = os.path.abspath(os.path.dirname(__file__))
+long_description = "\n\n".join(long_desc(HERE))
+
+
+def get_version(root_path):
+    with open(os.path.join(root_path, 'model_utils', '__init__.py')) as f:
         for line in f:
             if line.startswith('__version__ ='):
                 return line.split('=')[1].strip().strip('"\'')
 
 setup(
     name='django-model-utils',
-    version=get_version(),
+    version=get_version(HERE),
     description='Django model mixins and utilities',
     long_description=long_description,
     author='Carl Meyer',