Merge pull request #153 from google/release-0.5.9

Update for v0.5.9 release.
diff --git a/setup.py b/setup.py
index 017f13d..b035cdc 100644
--- a/setup.py
+++ b/setup.py
@@ -54,7 +54,7 @@
 if py_version < '2.7':
     REQUIRED_PACKAGES.append('argparse>=1.2.1')
 
-_APITOOLS_VERSION = '0.5.8'
+_APITOOLS_VERSION = '0.5.9'
 
 with open('README.rst') as fileobj:
     README = fileobj.read()