Pin PyYAML for Python 2.4.

setup.py

@@ -15,14 +15,18 @@
 __version__ = '0.7'
 
 import os
+import sys
 
 from setuptools import setup, find_packages
 
 here = os.path.abspath(os.path.dirname(__file__))
 README = open(os.path.join(here, 'README.txt')).read()
 CHANGES = open(os.path.join(here, 'CHANGES.txt')).read()
 
-requires = ['PyYAML']
+if sys.version_info >= (2, 5):
+    requires = ['PyYAML']
+else:
+    requires = ['PyYAML<3.10dev']
 
 setup(name='repoze.configuration',
       version=__version__,
@@ -47,6 +51,6 @@
       entry_points = """\
       [repoze.configuration.directive]
       include = repoze.configuration.directives:include
-      """
-      )
+      """,
+)