Update for v0.5.27 release. (#264)

diff --git a/setup.py b/setup.py
index cde9a49..1091486 100644
--- a/setup.py
+++ b/setup.py
@@ -49,7 +49,7 @@
 
 py_version = platform.python_version()
 
-_APITOOLS_VERSION = '0.5.26'
+_APITOOLS_VERSION = '0.5.27'
 
 with open('README.rst') as fileobj:
     README = fileobj.read()