Specify YAML requirement.

Author: rohe

setup.py

@@ -67,8 +67,8 @@ def run_tests(self):
         "Programming Language :: Python :: 3.9",
         "Topic :: Software Development :: Libraries :: Python Modules"],
     install_requires=[
-        'oidcmsg>=1.3.0',
-        'pyyaml',
+        'oidcmsg==1.3.2',
+        'pyyaml>=5.1.2',
         'responses'
     ],
     tests_require=[