Restrict google-cloud-ndb to <2.0.0 for pypi package. (#2883)

It introduces incompatibilities.

google/oss-fuzz#9151

Author: oliverchang

src/setup.py

@@ -19,7 +19,7 @@
 
 setuptools.setup(
     name='clusterfuzz',
-    version='2.5.6',
+    version='2.5.8',
     author='ClusterFuzz authors',
     author_email='clusterfuzz-dev@googlegroups.com',
     description='ClusterFuzz',
@@ -41,7 +41,7 @@
         'google-cloud-datastore==1.12.0',
         'google-cloud-logging',
         'google-cloud-monitoring',
-        'google-cloud-ndb',
+        'google-cloud-ndb<2.0.0',
         'google-cloud-storage',
         'grpcio',
         'httplib2',